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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds useful behavior beyond annotations: the response is the normalized app record, and missing ids return 404. It doesn't mention any rate limits or pagination, but none is clearly needed for a single-record lookup.

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?

Three short sentences with zero waste. The core fetch behavior is front-loaded, followed by response semantics and the search alternative, in that order.

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 single-parameter lookup with a 100%-covered schema, annotations, and an output schema, the description covers everything an agent needs: what it returns, what the id must be, where to get it, and what happens on a miss.

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%, and the schema already states that app_uid is the required exact id from datasets_apps_search. The description reinforces that provenance and exactness requirement but adds no new syntax or format details beyond the structured field, so baseline 3 is appropriate.

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: fetch one stored App Store or Google Play app record by exact app_uid. It also names the sibling datasets_apps_search as the source of ids, so the agent can tell it apart from search tools without opening the 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?

Explicitly directs the agent to use datasets_apps_search to find app ids, and clarifies that the id must be exact. The 404 behavior for absent ids gives a clear failure condition, so when-to-use vs. the search alternative is fully specified.

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