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

No annotations exist, so the description carries the full burden, and it does well: it discloses the account requirement, what still works unauthenticated (find_listing/get_store_listing read any store page), and a data caveat (the store may round the user count). It stops short of describing pagination, result caps, or rate limits for large portfolios.

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: the core output and the 'start here' routing appear first, with the auth/signup logistics last. The final paragraph is dense and slightly repetitive about the signup URL, but every sentence carries routing or auth information.

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 no output schema and no parameters, the description supplies the return-field inventory itself, plus the auth story and the fallback chain into sibling tools. Nothing an agent needs to select or call this tool is missing.

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?

The tool takes zero parameters, so the baseline is 4. There is nothing for the description to add beyond confirming that the listing is implicitly scoped to 'this token's owner', which it does.

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+resource (list every extension the token owner tracks) and enumerates the payload fields: user count with rounding flag, 7-day change, rating, ratings count, category rank. An agent can distinguish it from list_competitors/list_keywords/list_scrape_runs purely from this sentence.

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?

Explicitly says 'Start here when this connection has an account' and explains why: every tracking tool takes an extension_id from this list. It also names the alternative path — find_listing then get_store_listing — and states the condition (no account) that selects it.

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