cors_evaluate

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

No annotations are provided, so the description carries the full disclosure burden, and it does well: 'No network' establishes this as a pure, side-effect-free evaluation, and it enumerates the return shape (decision allow|block, violated rule IDs with clause references, missing headers, remediation headers). It stops short of explicitly stating determinism or that no state is mutated.

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?

Three dense, front-loaded sentences with no filler: purpose first, then output contract, then the no-network constraint. Every clause carries information an agent needs.

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?

An output schema exists, so return values need not be explained, yet the description still summarizes them usefully. Combined with 7 parameters at 86% schema coverage and the key 'no network' caveat, nothing material an agent needs in order to call this correctly is missing.

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?

Schema coverage is 86%, so the baseline is 3, but the description adds real meaning beyond the schema: 'url is parsed for scheme/host/port only' clarifies how the url parameter is consumed, refining the schema's 'only its origin is used.' It also frames response headers as the object to be judged, which sharpens the nested schema's intent.

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?

Specific verb and resource: 'Judge one HTTP response against the Fetch Standard CORS check,' with the scope constraint that only the URL's origin is used. This implicitly separates it from cors_simulate_fetch (this one does no network work and evaluates a given response), but no sibling is named, so sibling differentiation is inferred rather than explicit.

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?

Usage is implied by 'Judge one HTTP response' and by the statement that the URL is only parsed for scheme/host/port, telling the agent this tool takes an already-observed response. However, there is no explicit when-to-use, when-not-to-use, or named alternative (e.g. cors_simulate_fetch) for the case where the agent has no response yet.

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