Fix stats tool validation failures

src/domain/statistics.ts

@@ -83,13 +83,20 @@ export async function getVaultStatistics(context: DomainContext, args: { vaultPa
   let totalWords = 0;
   let totalLinks = 0;
   const tags = new Set<string>();
+  const skippedNotes: string[] = [];
 
   for (const absolutePath of await walkMarkdownFiles(vaultRoot)) {
     const relativePath = absolutePath.slice(vaultRoot.length + 1).replaceAll("\\", "/");
-    const noteStats = await getNoteStatistics(context, {
-      filePath: relativePath,
-      vaultPath: vaultRoot,
-    });
+    let noteStats: Awaited<ReturnType<typeof getNoteStatistics>>;
+    try {
+      noteStats = await getNoteStatistics(context, {
+        filePath: relativePath,
+        vaultPath: vaultRoot,
+      });
+    } catch {
+      skippedNotes.push(relativePath);
+      continue;
+    }
     totalNotes += 1;
     totalWords += noteStats.wordCount;
     totalLinks += noteStats.links.totalLinks;
@@ -105,5 +112,6 @@ export async function getVaultStatistics(context: DomainContext, args: { vaultPa
     uniqueTags: tags.size,
     allTags: [...tags].sort((left, right) => left.localeCompare(right)),
     avgWordsPerNote: Number((totalNotes > 0 ? totalWords / totalNotes : 0).toFixed(2)),
+    skippedNotes,
   };
 }

src/server/tools/notes.ts

@@ -51,6 +51,8 @@ import {
   mutationResultSchema,
 } from "../tool-schemas.js";
 
+type NoteStatistics = Awaited<ReturnType<typeof getNoteStatistics>>;
+
 async function handleEdit(context: DomainContext, args: NotesEditArgs) {
   if (args.mode === "replace") {
     return updateNote(context, {
@@ -93,6 +95,16 @@ async function handleEdit(context: DomainContext, args: NotesEditArgs) {
   });
 }
 
+function toNotesReadStats(stats: NoteStatistics) {
+  return {
+    ...stats,
+    words: stats.wordCount,
+    characters: stats.characterCount,
+    headings: stats.headings.count,
+    links: stats.links.totalLinks,
+  };
+}
+
 export const noteTools: ToolDefinition[] = [
   {
     name: "notes.read",
@@ -127,10 +139,11 @@ export const noteTools: ToolDefinition[] = [
       }
 
       if (wantStats) {
-        result.stats = await getNoteStatistics(context, {
+        const stats = await getNoteStatistics(context, {
           filePath: args.path,
           vaultPath: args.vaultPath,
         });
+        result.stats = toNotesReadStats(stats);
       }
 
       return result;

tests/server-integration.test.ts

@@ -1,3 +1,5 @@
+import { promises as fs } from "node:fs";
+import path from "node:path";
 import { Client } from "@modelcontextprotocol/sdk/client/index.js";
 import { StreamableHTTPClientTransport } from "@modelcontextprotocol/sdk/client/streamableHttp.js";
 import { InMemoryTransport } from "@modelcontextprotocol/sdk/inMemory.js";
@@ -46,6 +48,78 @@ describe("server integration", () => {
     await server.close();
   });
 
+  it("returns schema-compatible numeric note stats over MCP", async () => {
+    const vault = await makeTempVault();
+    const context = createDomainContext(
+      getEnv({
+        ...process.env,
+        OBSIDIAN_VAULT_PATH: vault,
+        KOBSIDIAN_ALLOWED_ORIGINS: "http://localhost",
+      }),
+    );
+    const server = createServer(context);
+    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();
+    await server.connect(serverTransport);
+    const client = new Client({ name: "stats-client", version: "1.0.0" }, { capabilities: {} });
+    await client.connect(clientTransport);
+
+    const result = await client.callTool({
+      name: "notes.read",
+      arguments: { path: "note1.md", include: ["stats"] },
+    });
+
+    expect(result.structuredContent).toMatchObject({
+      path: "note1.md",
+      stats: {
+        headings: expect.any(Number),
+        links: expect.any(Number),
+      },
+    });
+
+    await client.close();
+    await server.close();
+  });
+
+  it("keeps vault stats working when one note has unparseable frontmatter-like content", async () => {
+    const vault = await makeTempVault();
+    const windowsPath = String.raw`C:\Users\username\Documents\file.txt`;
+    await fs.writeFile(
+      path.join(vault, "confluence-export.md"),
+      [
+        "---json",
+        `{"source":"confluence","body":"\`\`\`powershell\\naws s3 cp \`'${windowsPath}'\` s3://bucket/\\n\`\`\`"}`,
+        "---",
+        "# Exported note",
+      ].join("\n"),
+      "utf8",
+    );
+    const context = createDomainContext(
+      getEnv({
+        ...process.env,
+        OBSIDIAN_VAULT_PATH: vault,
+        KOBSIDIAN_ALLOWED_ORIGINS: "http://localhost",
+      }),
+    );
+    const server = createServer(context);
+    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();
+    await server.connect(serverTransport);
+    const client = new Client(
+      { name: "vault-stats-client", version: "1.0.0" },
+      { capabilities: {} },
+    );
+    await client.connect(clientTransport);
+
+    const result = await client.callTool({ name: "stats.vault", arguments: {} });
+
+    expect(result.structuredContent).toMatchObject({
+      totalNotes: expect.any(Number),
+      skippedNotes: expect.arrayContaining(["confluence-export.md"]),
+    });
+
+    await client.close();
+    await server.close();
+  });
+
   it("serves the MCP endpoint over Streamable HTTP with Hono", async () => {
     const vault = await makeTempVault();
     const env = getEnv({