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

Annotations already declare read-only, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds real context beyond that: matching is fuzzy rather than exact, and the result spans two time views (live board and latest frozen week) plus an external page link.

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 sentence that front-loads the action, then the matching behavior, then the returned fields. No redundant restatement of the name or title.

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 one-parameter read tool with full annotations this is nearly complete, and the description compensates for the missing output schema by enumerating the returned fields. The one gap is behavior on a failed or ambiguous fuzzy match (no result, multiple candidates), which an agent would want to know.

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 baseline is 3, but the description genuinely extends the schema's 'App name, or part of it' by demonstrating that loose, multi-word, spaced queries are accepted. That is meaningful semantics an agent would not infer from the schema alone.

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 (find) and resource (app) plus exactly what is returned: rank on the live board, rank in the latest frozen week, and the ascension.fyi page. It is clearly a single-app lookup and thus implicitly distinct from the list-style siblings, but it never names movers or top_apps to make the distinction explicit.

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?

The fuzzy-match examples ('gemini', 'claude', 'chat gpt') tell the agent how to call it, but there is no guidance on when to prefer this over top_apps or movers, nor on prerequisites or failure behavior when the name matches nothing.

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