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

Annotations declare destructiveHint=true, idempotentHint=false and openWorldHint=true, yet the description reads like a harmless 'check' and discloses none of this – no mention of quota/credit consumption, repeated-run cost, or external network calls. The only behavioral addition is naming the AI surfaces (ChatGPT, Gemini, Perplexity), which is context, not behavioral disclosure.

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?

A single front-loaded sentence that identifies the action, the subject, and the value of the output with zero filler.

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 job-triggering, non-idempotent, potentially expensive tool with no output schema, the description should say what happens after the scan (results via get_visibility_results), whether it consumes credits, and how long it takes. It is adequate to identify the tool but incomplete for invoking it confidently.

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 site_id and the optional query are already documented in the schema. The description adds no format, scope, or defaulting detail beyond that, 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 (run) and resource (AI visibility scan) plus the concrete outcome: how the brand/site appears in AI-generated answers. It is distinguishable from the read-side siblings get_visibility_results and list_visibility_scans by implying a new scan is triggered, though it never names those alternatives.

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?

No when-to-use guidance, no prerequisites (e.g., site must exist or be connected), and no pointer to get_visibility_results/list_visibility_scans for retrieving results afterward. The agent is told what the tool does but not when to pick it over the sibling read tools.

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