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 that the output is a diff of two jobs, but discloses nothing further about comparison scope, limits, or what happens with mismatched jobs. With annotations carrying the safety burden, a 3 is appropriate.

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?

Two sentences, zero waste, with the core action front-loaded before the routing guidance. Every sentence earns its place.

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 low-complexity read tool with full schema coverage, annotations, and an output schema, the description covers purpose and alternatives adequately; return-value detail is correctly left to the output schema. It could go slightly further on what the diff covers, but nothing essential for calling it 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?

Schema description coverage is 100% and both job_id_a and job_id_b are documented in the schema, so the baseline is 3. The description only implies the two IDs are the compared jobs; it adds no format, ordering, or matching semantics beyond what the schema provides.

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 (compare) and resource (two APK teardown jobs) and clarifies scope with 'commonly versions of the same app' and 'return their differences.' An agent can distinguish this from the sibling change-view tools without opening any 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 routes the agent to alternatives: apk_teardown_submit to create jobs and apk_teardown_timeline / apk_teardown_compare_ownership for other change views. This gives clear when-to-use context, though the conditions selecting the alternatives are only loosely characterized ('other change views') rather than tightly specified.

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