mcp-policy-guardian

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden of behavioral disclosure. It effectively adds context beyond the input schema by stating 'network-free, read-only, fail-closed', which clarifies it's a local operation, safe (non-destructive), and has strict failure handling. It also hints at output structure with 'Stable keys: tool, repo_path, ok, checks, fail_closed'. This provides good behavioral insight, though more details on error conditions or performance could enhance it.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is highly concise and well-structured, with two sentences that efficiently convey purpose, behavioral traits, and output hints. Every phrase adds value without redundancy, making it easy to parse and front-loaded with key information. It effectively balances brevity with informativeness.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's moderate complexity (1 parameter, no annotations, but with an output schema), the description is reasonably complete. It covers purpose, behavioral traits, and hints at output structure, which compensates for the lack of annotations. The output schema existence reduces the need to detail return values, but more on parameter semantics or error handling could improve completeness. It's adequate for the context but has minor gaps.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema has 1 parameter with 0% description coverage, so the description must compensate. It mentions 'repo_path' as a 'stable key', implying it's a required input, but doesn't explain its meaning, format, or constraints. The description adds minimal semantic value beyond what's inferred from the schema, resulting in a baseline score due to the single parameter.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool performs a 'deterministic check for standard repository governance artifacts', which specifies both the action (check) and target (governance artifacts). It distinguishes itself by mentioning 'network-free, read-only, fail-closed' characteristics, though there are no sibling tools to differentiate from. The purpose is specific but not fully contrasted with alternatives.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage context through terms like 'deterministic', 'network-free', and 'fail-closed', suggesting it's for local, reliable checks. However, it lacks explicit guidance on when to use this tool versus alternatives, prerequisites, or specific scenarios. With no sibling tools, the need for differentiation is reduced, but general usage context remains implied rather than stated.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.