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

Annotations already cover the safe-read profile, and the description still adds substantial behavior: per-review quota cost (one per review per 30 days, free on re-read), App Store per-country vs Google Play per-language-from-all-countries semantics, and conditional url availability. This is exactly the context annotations cannot convey.

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 purpose and the sibling distinction, and nearly every sentence carries non-obvious information (quota, platform semantics, pagination). It is dense and runs long, though, with several ideas packed per sentence that bullet points would have surfaced faster.

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 14-parameter tool with an output schema, the description covers everything an agent needs: two input modes, pagination contract, platform scoping, quota economics, and response_format effects. Nothing material is left to inference.

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 93%, so the schema carries most parameter meaning (baseline 3). The description adds value above that base: review_ids should come from rivioo_search_reviews, next_cursor must be passed with the same arguments, and response_format's concise vs detailed field lists are spelled out.

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 (returns a page of full reviews of one app) and immediately distinguishes itself from rivioo_review_stats with 'reviews, not counts'. The sibling routing sentence makes the boundary crisp without opening any other 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?

Explicit when-to-use: use rivioo_search_reviews to count theme mentions, use this to read full reviews. It also names the two operating modes (review_ids for known reviews vs a window with filters for newest-first) and how to page with next_cursor using the same arguments.

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