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

Annotations only say readOnlyHint=false, idempotentHint=true and openWorldHint=true; the description explains why — one fetch of a public page with no credentials, redirects confined to the domain, result persisted and re-checked weekly. It also discloses concrete rate limits (ten an hour per address, twenty a day per listing) and the crucial side-effect boundary that grades/ranks/reviews are untouched.

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 mechanism, then constraints, then the use-condition and rate limits; nearly every clause carries information. It is a dense single paragraph, so the operational caveats (limits, weekly re-check) are buried mid-flow rather than being easy to scan.

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 two-parameter write-ish operation with no output schema, the description covers inputs, network behavior, persistence, side effects and throttling — enough to call it safely. It does not say what the caller receives (verified/pending/failed), which is the one gap an agent must discover at runtime.

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 both schema field descriptions already state the accepted URL locations and the slug forms. The prose largely restates those constraints ('on the listing's own domain, or in the README of its repository on GitHub'), adding only the fetch-scope detail rather than new per-parameter meaning, so the baseline 3 applies.

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 (verify/prove) and resource (a listing, on behalf of its vendor) plus the exact evidence it looks for (/badges/{slug}.svg or /tools/{slug}). An agent can distinguish this from check_server, get_tool or read_page without opening any schema.

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?

Explicit gating condition: 'Use it only when your user runs the product and has put the link there,' which excludes the common misuse of verifying someone else's listing. It also pre-empts a false expectation by stating it never changes grade, rank or review, and the slug schema note points agents back to search_tools for slug discovery.

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