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

Annotations already declare readOnly and non-destructive, so the description focuses on behavior the annotations can't express: the 14-day expiry threshold, the six specific defect classes, and the notable rule that no finding is written when both HTTP and HTTPS are unreachable. That last detail is genuinely non-obvious side-effect information an agent would otherwise have to discover by trial.

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?

Two sentences, front-loaded with the detected defect classes, followed by a single exception clause. Nothing is repeated and the caveat is placed after the main scope where it belongs.

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 conveys what kinds of results are produced (findings about cert/HTTPS state) and one condition under which no finding is written. What remains unstated is the shape of a returned finding (severity, message fields, per-protocol granularity), which is a modest gap for a diagnostic tool.

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 50%: the domain parameter is documented in the schema itself while outputFormat is only an enum with a default. The description adds no meaning to either parameter — no note on whether wildcards, ports, or subdomains are accepted in the domain string. Baseline 3 applies given the schema does the visible work.

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 definition opens with a specific verb and resource ("Check a publisher domain for HTTPS and certificate issues") and enumerates the exact failure modes it detects, so the scope is unmistakable. It doesn't explicitly name a sibling to distinguish itself from, but the subject matter (TLS/HTTPS) is clearly separate from the crawl/ads.txt/account tools listed.

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 only implied by the phrase "publisher domain" — there is no statement of when to prefer this over, say, check_crawler_blocks or run_agentic_readiness_audit. The closing sentence describes a result condition, not a reason to choose or avoid the tool.

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