diff --git a/src/index.ts b/src/index.ts
index ed72131..f0a8968 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -6,6 +6,9 @@ import { registerListProductsTool } from './tools/list-products.js'
 import { registerGetClaudeContextTool } from './tools/get-claude-context.js'
 import { registerUpdateTaskStatusTool } from './tools/update-task-status.js'
 import { registerUpdateTaskPlanTool } from './tools/update-task-plan.js'
+import { registerLogImplementationTool } from './tools/log-implementation.js'
+import { registerLogTestResultTool } from './tools/log-test-result.js'
+import { registerLogCommitTool } from './tools/log-commit.js'
 
 const VERSION = '0.1.0'
 
@@ -24,7 +27,10 @@ async function main() {
   registerGetClaudeContextTool(server)
   registerUpdateTaskStatusTool(server)
   registerUpdateTaskPlanTool(server)
-  // Log tools, create_todo and prompts in ST-707..ST-709.
+  registerLogImplementationTool(server)
+  registerLogTestResultTool(server)
+  registerLogCommitTool(server)
+  // create_todo and prompts in ST-708..ST-709.
 
   const transport = new StdioServerTransport()
   await server.connect(transport)
diff --git a/src/tools/log-commit.ts b/src/tools/log-commit.ts
new file mode 100644
index 0000000..01e86b0
--- /dev/null
+++ b/src/tools/log-commit.ts
@@ -0,0 +1,45 @@
+import { z } from 'zod'
+import type { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js'
+import { prisma } from '../prisma.js'
+import { requireWriteAccess } from '../auth.js'
+import { userCanAccessStory } from '../access.js'
+import { toolError, toolJson, withToolErrors } from '../errors.js'
+
+const inputSchema = z.object({
+  story_id: z.string().min(1),
+  content: z.string().min(1),
+  commit_hash: z.string().min(1),
+  commit_message: z.string().min(1),
+  metadata: z.record(z.string(), z.unknown()).optional(),
+})
+
+export function registerLogCommitTool(server: McpServer) {
+  server.registerTool(
+    'log_commit',
+    {
+      title: 'Log commit',
+      description:
+        'Append a COMMIT entry to a story log with hash and message. ' +
+        'Forbidden for demo accounts.',
+      inputSchema,
+    },
+    async ({ story_id, content, commit_hash, commit_message }) =>
+      withToolErrors(async () => {
+        const auth = await requireWriteAccess()
+        if (!(await userCanAccessStory(story_id, auth.userId))) {
+          return toolError(`Story ${story_id} not found or not accessible`)
+        }
+        const log = await prisma.storyLog.create({
+          data: {
+            story_id,
+            type: 'COMMIT',
+            content,
+            commit_hash,
+            commit_message,
+          },
+          select: { id: true, created_at: true },
+        })
+        return toolJson({ id: log.id, created_at: log.created_at })
+      }),
+  )
+}
diff --git a/src/tools/log-implementation.ts b/src/tools/log-implementation.ts
new file mode 100644
index 0000000..f12de38
--- /dev/null
+++ b/src/tools/log-implementation.ts
@@ -0,0 +1,43 @@
+import { z } from 'zod'
+import type { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js'
+import { prisma } from '../prisma.js'
+import { requireWriteAccess } from '../auth.js'
+import { userCanAccessStory } from '../access.js'
+import { toolError, toolJson, withToolErrors } from '../errors.js'
+
+// metadata is accepted on input but not yet written — schema sync after
+// Scrum4Me PR #2 lands adds the StoryLog.metadata JSONB column.
+const inputSchema = z.object({
+  story_id: z.string().min(1),
+  content: z.string().min(1),
+  metadata: z.record(z.string(), z.unknown()).optional(),
+})
+
+export function registerLogImplementationTool(server: McpServer) {
+  server.registerTool(
+    'log_implementation',
+    {
+      title: 'Log implementation plan',
+      description:
+        'Append an IMPLEMENTATION_PLAN entry to a story log. ' +
+        'Forbidden for demo accounts.',
+      inputSchema,
+    },
+    async ({ story_id, content }) =>
+      withToolErrors(async () => {
+        const auth = await requireWriteAccess()
+        if (!(await userCanAccessStory(story_id, auth.userId))) {
+          return toolError(`Story ${story_id} not found or not accessible`)
+        }
+        const log = await prisma.storyLog.create({
+          data: {
+            story_id,
+            type: 'IMPLEMENTATION_PLAN',
+            content,
+          },
+          select: { id: true, created_at: true },
+        })
+        return toolJson({ id: log.id, created_at: log.created_at })
+      }),
+  )
+}
diff --git a/src/tools/log-test-result.ts b/src/tools/log-test-result.ts
new file mode 100644
index 0000000..d6eaa05
--- /dev/null
+++ b/src/tools/log-test-result.ts
@@ -0,0 +1,43 @@
+import { z } from 'zod'
+import type { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js'
+import { prisma } from '../prisma.js'
+import { requireWriteAccess } from '../auth.js'
+import { userCanAccessStory } from '../access.js'
+import { toolError, toolJson, withToolErrors } from '../errors.js'
+
+const inputSchema = z.object({
+  story_id: z.string().min(1),
+  content: z.string().min(1),
+  status: z.enum(['PASSED', 'FAILED']),
+  metadata: z.record(z.string(), z.unknown()).optional(),
+})
+
+export function registerLogTestResultTool(server: McpServer) {
+  server.registerTool(
+    'log_test_result',
+    {
+      title: 'Log test result',
+      description:
+        'Append a TEST_RESULT entry (PASSED or FAILED) to a story log. ' +
+        'Forbidden for demo accounts.',
+      inputSchema,
+    },
+    async ({ story_id, content, status }) =>
+      withToolErrors(async () => {
+        const auth = await requireWriteAccess()
+        if (!(await userCanAccessStory(story_id, auth.userId))) {
+          return toolError(`Story ${story_id} not found or not accessible`)
+        }
+        const log = await prisma.storyLog.create({
+          data: {
+            story_id,
+            type: 'TEST_RESULT',
+            content,
+            status,
+          },
+          select: { id: true, created_at: true },
+        })
+        return toolJson({ id: log.id, created_at: log.created_at })
+      }),
+  )
+}