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

Annotations only cover the safety profile (readOnly, openWorld, non-destructive). The description adds substantial behavior beyond them: no redirect following, no body fetch, one server vantage, and a concrete rate limit (10 attempts per IP per 24h, honor Retry-After).

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?

Front-loaded with the core action and densely packed with constraints in a few lines, with no filler. The telegraphic phrasing ('one server vantage and one selected address') is slightly terse but not wasteful.

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, and the description still signals the return shape (cause, evidence, suggested_action) while covering scope limits, rate limits, and vantage caveats. Nothing essential for correct invocation 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?

With one param and 0% schema description coverage, the description carries the burden and does add meaning: the URL must be public, ports restricted to 80/443, no credentials/query strings/fragments. It explains valid input shape even though the schema itself is bare.

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 (diagnose) and resource (one public HTTP(S) URL) with the exact probe steps (DNS, TCP, verified TLS, HTTP HEAD). This distinguishes it from siblings like probe_me_now and agent_endpoint_assessment without opening their schemas.

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?

Gives clear preconditions (public URL, no registration, only ports 80/443) and explicit when-not scope ('not browser compatibility or application health proof'). It stops short of naming which sibling to use instead for related checks, so it is clear context but lacks explicit routing.

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