perf_check_headers

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

With no annotations, the description carries the full burden of behavioral disclosure. It implies the tool makes an HTTP request to the target URL and inspects response headers, which is a read-only audit. However, it does not explicitly state that no modifications are made, nor does it disclose any potential latency or failure behavior. It is adequate but not explicit about side effects or limitations.

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 a single, well-formed sentence that front-loads the action and clearly enumerates the scope. There is no wasted wording, and it is appropriately concise for a tool with one parameter.

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 simplicity of the tool (one parameter, no output schema), the description gives a clear picture of the audit scope. However, it does not describe what the tool returns (e.g., a report or findings) or any assumptions about the target (e.g., server must be running). While not critical, a bit more context on output could improve completeness.

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 single parameter 'url' is fully described in the schema with an example, so schema coverage is 100%. The description adds no additional meaning beyond what the schema provides, so a baseline score of 3 is appropriate.

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 a specific verb ('Audits') and resource ('HTTP response headers of a web application'), and then specifies the exact aspects checked (Gzip/Brotli compression, Cache-Control, and security headers). This distinguishes it from the sibling perf_audit_assets, which targets assets rather than headers.

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 provides no explicit guidance on when to use this tool versus alternatives, nor does it mention any exclusions or prerequisites. It simply states what it does, leaving the agent to infer when it is appropriate. Among siblings like perf_audit_assets, there is no comparative guidance.

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