diff --git a/src/tools/hashline-edit/hashline-edit-executor.ts b/src/tools/hashline-edit/hashline-edit-executor.ts
index 96db35233..777ae1622 100644
--- a/src/tools/hashline-edit/hashline-edit-executor.ts
+++ b/src/tools/hashline-edit/hashline-edit-executor.ts
@@ -1,14 +1,14 @@
 import type { ToolContext } from "@opencode-ai/plugin/tool"
 import { storeToolMetadata } from "../../features/tool-metadata-store"
 import { applyHashlineEditsWithReport } from "./edit-operations"
-import { countLineDiffs, generateUnifiedDiff, toHashlineContent } from "./diff-utils"
+import { countLineDiffs, generateUnifiedDiff } from "./diff-utils"
 import { canonicalizeFileText, restoreFileText } from "./file-text-canonicalization"
-import { generateHashlineDiff } from "./hashline-edit-diff"
+import { normalizeHashlineEdits, type RawHashlineEdit } from "./normalize-edits"
 import type { HashlineEdit } from "./types"
 
 interface HashlineEditArgs {
   filePath: string
-  edits: HashlineEdit[]
+  edits: RawHashlineEdit[]
   delete?: boolean
   rename?: string
 }
@@ -44,6 +44,17 @@ function buildSuccessMeta(
 ) {
   const unifiedDiff = generateUnifiedDiff(beforeContent, afterContent, effectivePath)
   const { additions, deletions } = countLineDiffs(beforeContent, afterContent)
+  const beforeLines = beforeContent.split("\n")
+  const afterLines = afterContent.split("\n")
+  const maxLength = Math.max(beforeLines.length, afterLines.length)
+  let firstChangedLine: number | undefined
+
+  for (let index = 0; index < maxLength; index += 1) {
+    if ((beforeLines[index] ?? "") !== (afterLines[index] ?? "")) {
+      firstChangedLine = index + 1
+      break
+    }
+  }
 
   return {
     title: effectivePath,
@@ -54,6 +65,7 @@ function buildSuccessMeta(
       diff: unifiedDiff,
       noopEdits,
       deduplicatedEdits,
+      firstChangedLine,
       filediff: {
         file: effectivePath,
         path: effectivePath,
@@ -71,14 +83,17 @@ export async function executeHashlineEditTool(args: HashlineEditArgs, context: T
   try {
     const metadataContext = context as ToolContextWithMetadata
     const filePath = args.filePath
-    const { edits, delete: deleteMode, rename } = args
+    const { delete: deleteMode, rename } = args
+
+    if (!deleteMode && (!args.edits || !Array.isArray(args.edits) || args.edits.length === 0)) {
+      return "Error: edits parameter must be a non-empty array"
+    }
+
+    const edits = deleteMode ? [] : normalizeHashlineEdits(args.edits)
 
     if (deleteMode && rename) {
       return "Error: delete and rename cannot be used together"
     }
-    if (!deleteMode && (!edits || !Array.isArray(edits) || edits.length === 0)) {
-      return "Error: edits parameter must be a non-empty array"
-    }
     if (deleteMode && edits.length > 0) {
       return "Error: delete mode requires edits to be an empty array"
     }
@@ -100,6 +115,15 @@ export async function executeHashlineEditTool(args: HashlineEditArgs, context: T
 
     const applyResult = applyHashlineEditsWithReport(oldEnvelope.content, edits)
     const canonicalNewContent = applyResult.content
+
+    if (canonicalNewContent === oldEnvelope.content && !rename) {
+      let diagnostic = `No changes made to ${filePath}. The edits produced identical content.`
+      if (applyResult.noopEdits > 0) {
+        diagnostic += ` No-op edits: ${applyResult.noopEdits}. Re-read the file and provide content that differs from current lines.`
+      }
+      return `Error: ${diagnostic}`
+    }
+
     const writeContent = restoreFileText(canonicalNewContent, oldEnvelope)
 
     await Bun.write(filePath, writeContent)
@@ -110,8 +134,6 @@ export async function executeHashlineEditTool(args: HashlineEditArgs, context: T
     }
 
     const effectivePath = rename && rename !== filePath ? rename : filePath
-    const diff = generateHashlineDiff(oldEnvelope.content, canonicalNewContent, effectivePath)
-    const newHashlined = toHashlineContent(canonicalNewContent)
     const meta = buildSuccessMeta(
       effectivePath,
       oldEnvelope.content,
@@ -129,13 +151,11 @@ export async function executeHashlineEditTool(args: HashlineEditArgs, context: T
       storeToolMetadata(context.sessionID, callID, meta)
     }
 
-    return `Successfully applied ${edits.length} edit(s) to ${effectivePath}
-No-op edits: ${applyResult.noopEdits}, deduplicated edits: ${applyResult.deduplicatedEdits}
+    if (rename && rename !== filePath) {
+      return `Moved ${filePath} to ${rename}`
+    }
 
-${diff}
-
-Updated file (LINE#ID:content):
-${newHashlined}`
+    return `Updated ${effectivePath}`
   } catch (error) {
     const message = error instanceof Error ? error.message : String(error)
     if (message.toLowerCase().includes("hash")) {
diff --git a/src/tools/hashline-edit/normalize-edits.ts b/src/tools/hashline-edit/normalize-edits.ts
new file mode 100644
index 000000000..b4e49d382
--- /dev/null
+++ b/src/tools/hashline-edit/normalize-edits.ts
@@ -0,0 +1,142 @@
+import type { HashlineEdit } from "./types"
+
+export interface RawHashlineEdit {
+  type?:
+    | "set_line"
+    | "replace_lines"
+    | "insert_after"
+    | "insert_before"
+    | "insert_between"
+    | "replace"
+    | "append"
+    | "prepend"
+  line?: string
+  start_line?: string
+  end_line?: string
+  after_line?: string
+  before_line?: string
+  text?: string | string[]
+  old_text?: string
+  new_text?: string | string[]
+}
+
+function firstDefined(...values: Array<string | undefined>): string | undefined {
+  for (const value of values) {
+    if (typeof value === "string" && value.trim() !== "") return value
+  }
+  return undefined
+}
+
+function requireText(edit: RawHashlineEdit, index: number): string | string[] {
+  const text = edit.text ?? edit.new_text
+  if (text === undefined) {
+    throw new Error(`Edit ${index}: text is required for ${edit.type ?? "unknown"}`)
+  }
+  return text
+}
+
+function requireLine(anchor: string | undefined, index: number, op: string): string {
+  if (!anchor) {
+    throw new Error(`Edit ${index}: ${op} requires at least one anchor line reference`)
+  }
+  return anchor
+}
+
+export function normalizeHashlineEdits(rawEdits: RawHashlineEdit[]): HashlineEdit[] {
+  const normalized: HashlineEdit[] = []
+
+  for (let index = 0; index < rawEdits.length; index += 1) {
+    const edit = rawEdits[index] ?? {}
+    const type = edit.type
+
+    switch (type) {
+      case "set_line": {
+        const anchor = firstDefined(edit.line, edit.start_line, edit.end_line, edit.after_line, edit.before_line)
+        normalized.push({
+          type: "set_line",
+          line: requireLine(anchor, index, "set_line"),
+          text: requireText(edit, index),
+        })
+        break
+      }
+      case "replace_lines": {
+        const startAnchor = firstDefined(edit.start_line, edit.line, edit.after_line)
+        const endAnchor = firstDefined(edit.end_line, edit.line, edit.before_line)
+
+        if (!startAnchor && !endAnchor) {
+          throw new Error(`Edit ${index}: replace_lines requires start_line or end_line`)
+        }
+
+        if (startAnchor && endAnchor) {
+          normalized.push({
+            type: "replace_lines",
+            start_line: startAnchor,
+            end_line: endAnchor,
+            text: requireText(edit, index),
+          })
+        } else {
+          normalized.push({
+            type: "set_line",
+            line: requireLine(startAnchor ?? endAnchor, index, "replace_lines"),
+            text: requireText(edit, index),
+          })
+        }
+        break
+      }
+      case "insert_after": {
+        const anchor = firstDefined(edit.line, edit.after_line, edit.end_line, edit.start_line)
+        normalized.push({
+          type: "insert_after",
+          line: requireLine(anchor, index, "insert_after"),
+          text: requireText(edit, index),
+        })
+        break
+      }
+      case "insert_before": {
+        const anchor = firstDefined(edit.line, edit.before_line, edit.start_line, edit.end_line)
+        normalized.push({
+          type: "insert_before",
+          line: requireLine(anchor, index, "insert_before"),
+          text: requireText(edit, index),
+        })
+        break
+      }
+      case "insert_between": {
+        const afterLine = firstDefined(edit.after_line, edit.line, edit.start_line)
+        const beforeLine = firstDefined(edit.before_line, edit.end_line, edit.line)
+        normalized.push({
+          type: "insert_between",
+          after_line: requireLine(afterLine, index, "insert_between.after_line"),
+          before_line: requireLine(beforeLine, index, "insert_between.before_line"),
+          text: requireText(edit, index),
+        })
+        break
+      }
+      case "replace": {
+        const oldText = edit.old_text
+        const newText = edit.new_text ?? edit.text
+        if (!oldText) {
+          throw new Error(`Edit ${index}: replace requires old_text`)
+        }
+        if (newText === undefined) {
+          throw new Error(`Edit ${index}: replace requires new_text or text`)
+        }
+        normalized.push({ type: "replace", old_text: oldText, new_text: newText })
+        break
+      }
+      case "append": {
+        normalized.push({ type: "append", text: requireText(edit, index) })
+        break
+      }
+      case "prepend": {
+        normalized.push({ type: "prepend", text: requireText(edit, index) })
+        break
+      }
+      default: {
+        throw new Error(`Edit ${index}: unsupported type "${String(type)}"`)
+      }
+    }
+  }
+
+  return normalized
+}
diff --git a/src/tools/hashline-edit/tools.ts b/src/tools/hashline-edit/tools.ts
index dcb718cb5..98a258949 100644
--- a/src/tools/hashline-edit/tools.ts
+++ b/src/tools/hashline-edit/tools.ts
@@ -1,11 +1,11 @@
 import { tool, type ToolContext, type ToolDefinition } from "@opencode-ai/plugin/tool"
-import type { HashlineEdit } from "./types"
 import { executeHashlineEditTool } from "./hashline-edit-executor"
 import { HASHLINE_EDIT_DESCRIPTION } from "./tool-description"
+import type { RawHashlineEdit } from "./normalize-edits"
 
 interface HashlineEditArgs {
   filePath: string
-  edits: HashlineEdit[]
+  edits: RawHashlineEdit[]
   delete?: boolean
   rename?: string
 }
@@ -19,64 +19,34 @@ export function createHashlineEditTool(): ToolDefinition {
       rename: tool.schema.string().optional().describe("Rename output file path after edits"),
       edits: tool.schema
         .array(
-          tool.schema.union([
-            tool.schema.object({
-              type: tool.schema.literal("set_line"),
-              line: tool.schema.string().describe("Line reference in LINE#ID format"),
-              text: tool.schema
-                .union([tool.schema.string(), tool.schema.array(tool.schema.string())])
-                .describe("New content for the line (string or string[] for multiline)"),
-            }),
-            tool.schema.object({
-              type: tool.schema.literal("replace_lines"),
-              start_line: tool.schema.string().describe("Start line in LINE#ID format"),
-              end_line: tool.schema.string().describe("End line in LINE#ID format"),
-              text: tool.schema
-                .union([tool.schema.string(), tool.schema.array(tool.schema.string())])
-                .describe("New content to replace the range (string or string[] for multiline)"),
-            }),
-            tool.schema.object({
-              type: tool.schema.literal("insert_after"),
-              line: tool.schema.string().describe("Line reference in LINE#ID format"),
-              text: tool.schema
-                .union([tool.schema.string(), tool.schema.array(tool.schema.string())])
-                .describe("Content to insert after the line (string or string[] for multiline)"),
-            }),
-            tool.schema.object({
-              type: tool.schema.literal("insert_before"),
-              line: tool.schema.string().describe("Line reference in LINE#ID format"),
-              text: tool.schema
-                .union([tool.schema.string(), tool.schema.array(tool.schema.string())])
-                .describe("Content to insert before the line (string or string[] for multiline)"),
-            }),
-            tool.schema.object({
-              type: tool.schema.literal("insert_between"),
-              after_line: tool.schema.string().describe("After line in LINE#ID format"),
-              before_line: tool.schema.string().describe("Before line in LINE#ID format"),
-              text: tool.schema
-                .union([tool.schema.string(), tool.schema.array(tool.schema.string())])
-                .describe("Content to insert between anchor lines (string or string[] for multiline)"),
-            }),
-            tool.schema.object({
-              type: tool.schema.literal("replace"),
-              old_text: tool.schema.string().describe("Text to find"),
-              new_text: tool.schema
-                .union([tool.schema.string(), tool.schema.array(tool.schema.string())])
-                .describe("Replacement text (string or string[] for multiline)"),
-            }),
-            tool.schema.object({
-              type: tool.schema.literal("append"),
-              text: tool.schema
-                .union([tool.schema.string(), tool.schema.array(tool.schema.string())])
-                .describe("Content to append at EOF; also creates missing file"),
-            }),
-            tool.schema.object({
-              type: tool.schema.literal("prepend"),
-              text: tool.schema
-                .union([tool.schema.string(), tool.schema.array(tool.schema.string())])
-                .describe("Content to prepend at BOF; also creates missing file"),
-            }),
-          ])
+          tool.schema.object({
+            type: tool.schema
+              .union([
+                tool.schema.literal("set_line"),
+                tool.schema.literal("replace_lines"),
+                tool.schema.literal("insert_after"),
+                tool.schema.literal("insert_before"),
+                tool.schema.literal("insert_between"),
+                tool.schema.literal("replace"),
+                tool.schema.literal("append"),
+                tool.schema.literal("prepend"),
+              ])
+              .describe("Edit operation type"),
+            line: tool.schema.string().optional().describe("Anchor line in LINE#ID format"),
+            start_line: tool.schema.string().optional().describe("Range start in LINE#ID format"),
+            end_line: tool.schema.string().optional().describe("Range end in LINE#ID format"),
+            after_line: tool.schema.string().optional().describe("Insert boundary (after) in LINE#ID format"),
+            before_line: tool.schema.string().optional().describe("Insert boundary (before) in LINE#ID format"),
+            text: tool.schema
+              .union([tool.schema.string(), tool.schema.array(tool.schema.string())])
+              .optional()
+              .describe("Operation content"),
+            old_text: tool.schema.string().optional().describe("Legacy text replacement source"),
+            new_text: tool.schema
+              .union([tool.schema.string(), tool.schema.array(tool.schema.string())])
+              .optional()
+              .describe("Legacy text replacement target"),
+          })
         )
         .describe("Array of edit operations to apply (empty when delete=true)"),
     },