HTTP security headers (1 GET)

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

Annotations already supply readOnlyHint=true and openWorldHint=true, so safety is partly covered. The description adds real behavioral limits beyond that: the check is passive and derived from one GET of the homepage only, so the agent knows it will not crawl subpages or probe actively. It still does not say what the grade scale is or how version-leaking headers are reported.

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?

A single front-loaded sentence stating scope, evidence source, and the concrete header list. The parenthetical enumeration is long but earns its place by telling the agent exactly what the grade covers; only the trailing "Passive." is terse to the point of ambiguity.

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?

With no output schema, the description must hint at returns, and it does (a grade plus flagging of version-leaking headers). Combined with the explicit header set and the single-GET scope limit, an agent has enough to call it correctly; only the grade scale and result shape remain unspecified.

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?

One required parameter with 0% schema description coverage, so the description must carry the load. "A site's ... homepage" conveys that the input is a site/domain rather than a full URL, but it gives no format, scheme, or subdomain guidance for the domain string.

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 (grade) plus specific resource (HTTP security headers) with the exact header set enumerated, so the agent knows precisely what is inspected. Nothing in the sibling list (breach/cve/subdomain tools) overlaps, and the tool is immediately distinguishable.

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?

"Passive" and "from a single GET of its homepage" imply the context (non-intrusive check of one page), but there is no explicit when-to-use statement, no stated preconditions, and no named alternative. With no sibling covering header assessment, usage is only implied.

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