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

Annotations already declare read-only, idempotent, closed-world, non-destructive, so the safety profile is covered; the description adds behavior the annotations cannot express — results are paginated via next_cursor, and the default cohort silently limits rows to core prompts. Those are the two traits most likely to cause an agent to misread an empty or short result set, and both are disclosed.

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 what the tool returns, then the required-input warning, then pagination, then scoping defaults, then filter behavior, then sibling routing. Every sentence carries a distinct fact and none repeats the schema verbatim.

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?

Nine parameters and no output schema, so the description carries the return-shape burden — and it does, enumerating prompt text, engine, model, repetition, web-search flag, brands with first position, citations with URL/domain/own-vs-competitor, and a citeladder:// id for fetch. Combined with the pagination and cohort notes, an agent has everything needed to call and interpret it.

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%, so the schema already documents each parameter and a baseline 3 would apply. The description goes beyond it by stating that filters (prompt_id, domain, url, engine) combine — an interaction the schema does not express — and by tying audit_id to its source in read_visibility_overview; the cursor/next_cursor round-trip is described though the parameter is named 'cursor'.

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 — read the answers engines gave in one run — and immediately names the two siblings it is not (read_visibility_overview for rates, read_visibility_sources for citation totals). An agent can distinguish it from the other visibility tools 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?

Gives explicit routing rules: use overview for rates, sources for citation totals, this tool for per-answer text. It also states the prerequisite (audit_id comes from read_visibility_overview) and the default scoping caveat (only core prompts unless cohort is comparison or all), which is exactly the kind of when-to-use guidance that prevents wrong calls.

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