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

Annotations already cover readOnly, idempotent, non-destructive and open-world, and the description adds real value on top: an explicit cost of 6 fetches, the exact diagnostic sequence, the result vocabulary (ruled_out/suspect/confirmed/unknown) with evidence, and a pointer to the equivalent web tool. That is precisely the behavioral context an agent needs before spending fetches on an open-world call.

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 purpose, then the check list, the result shape, the cost, and the web equivalent. The parenthetical enumeration is dense but each item carries diagnostic meaning; nothing pads.

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 one-parameter, no-output-schema tool this is complete: the agent knows the trigger, what is inspected, what the result categories mean, what evidence accompanies them, and the fetch cost. No output schema is needed because the description names the return vocabulary.

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 100% and the single url parameter is documented in the schema (absolute http(s) URL or hostname with https assumed). The description adds nothing about the parameter, so this is the baseline-3 case where the schema does all the 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?

States a specific verb (triage) and resource (a domain that disappeared from Google) and enumerates the nine checks it performs in crawl-then-index order. This clearly distinguishes it from the single-check siblings like stillindexed_check_robots or stillindexed_check_tls: this one is the composite diagnostic.

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?

"Triage a domain that disappeared from Google" gives a clear triggering context, and the ordered list implies it supersedes running the individual checks one at a time. It never explicitly says when-not to use it or names the narrower siblings as alternatives, so it falls short of a 5.

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