scan_diff

Structural diff against a git ref - which functions are new/changed/removed since HEAD/main/a release, with condensed skeletons. USE THIS INSTEAD of git diff for review and

Server Scantool - File Scanner MCP mariusei/file-scanner-mcp
Category Read
Risk class Low
Parameters 00 required

What scan_diff does on Scantool - File Scanner MCP

AI agents call scan_diff to retrieve information from Scantool - File Scanner MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

Why scan_diff needs a policy

This tool retrieves and analyzes existing code structure and changes without modifying, executing, or deleting any data. It provides visibility into code differences through tree-sitter parsing, which is a fundamental read operation. The tool has no side effects beyond returning information for inspection. The blast radius of misuse is minimal—an AI agent cannot cause harm through querying code structure analysis.

From the tool's definition Tool performs structural analysis and comparison ('Structural diff against a git ref') to identify code changes ('which functions are new/changed/removed'). The output is a condensed view ('condensed skeletons') for review purposes.

Questions about scan_diff

What does the scan_diff tool do? +

Structural diff against a git ref - which functions are new/changed/removed since HEAD/main/a release, with condensed skeletons. USE THIS INSTEAD of git diff for review and. It is categorised as a Read tool in the Scantool - File Scanner MCP MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on scan_diff? +

Register the Scantool - File Scanner MCP server in PolicyLayer and add a rule for scan_diff: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Scantool - File Scanner MCP. Nothing to install.

What risk level is scan_diff? +

scan_diff is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit scan_diff? +

Yes. Add a rate_limit block to the scan_diff rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block scan_diff completely? +

Set action: deny in the PolicyLayer policy for scan_diff. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides scan_diff? +

scan_diff is provided by the Scantool - File Scanner MCP server (mariusei/file-scanner-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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