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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds substantive behavior beyond that: it discloses the untrusted-text fields (title, body, author_name, reply) as a prompt-injection guard, and explains two non-obvious states — setup_required (no app connected, don't report zero reviews) and syncing (first sync still running) — with prescribed agent handling.

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 it returns, followed by the use case, an example, and two error-handling rules. Every sentence carries operational value; nothing is restated from the schema or annotations.

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?

Output schema exists so return fields needn't be enumerated, yet the description flags the untrusted ones for safety. Combined with error-state guidance and id provenance, an agent has everything needed to call it correctly and interpret failures.

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% and the single parameter is already fully documented and format-constrained, so the baseline is a 3. The description adds a concrete example payload and reinforces provenance ('<id from get_app_reviews>'), giving a modest lift.

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 with scope: fetches ONE review by id, including its posted developer reply. The 'one review by id' framing implicitly separates it from list/search siblings like get_app_reviews and search_reviews, though it never names them as alternatives for retrieval.

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 a concrete use case ('show the full text before drafting a reply'), tying it to draft_reply, and points at get_app_reviews as the id source. No explicit when-not-to-use clause, but the context is clear enough to route correctly.

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