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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and a closed world, so the safety profile is covered. The description adds real value by disclosing what the result contains (confidence tier, overall rank, rank within source role, per-category rates), which is the only place that information exists since there is no output schema.

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: the first front-loads the scope and the returned fields, the second supplies the use-case triggers. No filler, though the enumeration of output fields is fairly dense.

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 one required parameter, no output schema, and annotations covering safety, the description supplies the needed return-value detail and intent framing. Pagination and error/empty-result behavior are not covered, which is the only remaining gap for a read-only lookup.

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 description coverage is 100% and the single 'domain' parameter already explains 'a domain (techcrunch.com) or any URL on it.' The description restates the same 'domain or URL' flexibility without adding syntax, normalization, or error behavior, 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 and resource ('return how often AI answer engines cite it') scoped to a single domain or URL, and enumerates the returned metrics (citation rate, engines, confidence tier, ranks, segment rates). It differentiates implicitly from the list-oriented siblings by being per-domain, but never names an alternative, so it falls short of a 5.

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 concrete triggering questions — 'does ChatGPT/Perplexity cite <site>' and 'how authoritative is <publication> as an AI source' — which clearly frames when to reach for it. It offers no exclusions or explicit pointers to mri_get_cited_sources/mri_get_category for the aggregate case, so it stops 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.