pr-diff

Returns file-level diff statistics for a pull request. Use full=true for patch/hunk content, or nameOnly=true for just the changed file paths.

SERVERGithub SOURCE@paretools/github

Low RISK CLASS

Category Read

Parameters 00 required

Recommended Allowedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/io-github-dave-london-github/pr-diff.md

WHAT IT DOES

What pr-diff does on Github

AI agents call pr-diff to retrieve information from Github without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

RISK

Why pr-diff is rated Low

The pr-diff tool queries and retrieves pull request diff information from GitHub. It supports two read-only modes: returning detailed patch content (full=true) or just file paths (nameOnly=true). Both are data retrieval operations with no side effects, mutations, or external command execution. This is a classic Read category tool.

From the tool's definition Tool description explicitly states it 'Returns file-level diff statistics' with options for 'patch/hunk content' or 'changed file paths' — purely retrieval operations with no modification, deletion, or execution semantics.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs pr-diff safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Github, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For pr-diff, this is the rule to start with:

pr-diff Allowed

pr-diff is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "pr-diff": {}
  }
}

ALLOW ONLY THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Github, apply this rule, and every pr-diff call is checked against it from then on.

FAQ

Questions about pr-diff

What does the pr-diff tool do? +

Returns file-level diff statistics for a pull request. Use full=true for patch/hunk content, or nameOnly=true for just the changed file paths. It is categorised as a Read tool in the Github MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on pr-diff? +

Register the Github MCP server in PolicyLayer and add a rule for pr-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 Github. Nothing to install.

What risk level is pr-diff? +

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

Can I rate-limit pr-diff? +

Yes. Add a rate_limit block to the pr-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 pr-diff completely? +

Set action: deny in the PolicyLayer policy for pr-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 pr-diff? +

pr-diff is provided by the Github MCP server (@paretools/github). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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