security_headers

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

With no annotations, the description carries the full burden. It usefully discloses that the tool is defensive/informational and does not probe, exploit, or attack, and the timeoutMs parameter implies a live network request. However it does not say whether redirects are followed, whether it requires any auth, or what the request costs.

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 header scope is front-loaded well, but the safety statement is duplicated almost verbatim ('DEFENSIVE/INFORMATIONAL ONLY — does not probe, exploit, or attack' then 'Defensive/informational checks only — no exploit or attack tooling'). One of the two sentences could be cut without losing information.

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?

For a simple, read-only inspection tool with full schema coverage and no output schema, the description adequately conveys what is checked and the safety boundary. The missing piece is what the response looks like (per-header pass/fail list), which is only loosely implied by 'checklist'.

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 description coverage is 100%, so both parameters (url and timeoutMs) are already documented with their meaning and defaults in the schema. The description adds no format, validation, or URL-normalization details beyond that. Baseline 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?

States a specific verb+resource: checking presence/absence of common security headers, with concrete examples (CSP, HSTS, X-Frame-Options). An agent can distinguish this from http_status, broken_links, and seo_basics by the resource inspected, though the description never names those siblings explicitly.

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?

It gives a constraint ('only use on sites you own or have explicit permission to test') rather than routing guidance. There is no statement of when to prefer this over http_status or broken_links, so the user must infer the use case from the purpose.

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