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

With openWorldHint=true, idempotentHint=false and readOnlyHint=false already declared, the description adds real context: it discloses that live external queries are made, the exact question count and style, the return payload, and a 24-hour cache that re-serves prior results instead of re-asking. That explains the non-idempotent annotation rather than contradicting it. It still doesn't say what happens on failure or query cost/latency.

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?

Three sentences, each earning its place: trigger, mechanism, caching. The trigger is front-loaded and there is no redundant restatement of the title or name.

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?

No output schema exists, so the description correctly spends words on the return shape (each question, cited sites, whether this site was cited, date) and on the caching behavior. Parameters are covered by the schema. The only gap is failure/error behavior and any statement about scope or cost limits.

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%, so both parameters are already documented, and the baseline is 3. The description adds meaning for `url` (the site whose citations are checked, and the source of the generated questions) but says nothing about `brand`, so it does not meaningfully exceed the schema.

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 (check whether AI answer engines cite a website) and pins down the mechanism: one answer engine (Perplexity), three customer-style questions drawn from the site's own pages. That level of specificity distinguishes it from siblings like run_audit and get_public_report without requiring the agent to open 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?

"Use this when the user asks whether AI answer engines cite their website" gives an explicit trigger condition. It does not name alternatives or exclusions (e.g. when to prefer run_audit or get_public_report), and it says "engines" plural while only Perplexity is actually queried, but the primary when-to-use signal is clear.

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