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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the agent knows this is a safe read. The description adds only the typical-use framing and says nothing about behavior such as what happens if the two jobs are still running, whether the diff is partial, or result size limits.

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?

A single front-loaded sentence that names the action first and the typical scenario second. Nothing is wasted and nothing is buried.

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 an output schema present and full parameter coverage, the description needn't explain return values. It is minimally adequate for a simple two-parameter read tool, but it omits the prerequisite that both jobs must exist/completed and gives no tie-break against the compare_ownership sibling.

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% for both job_id_a and job_id_b, so the schema already documents the parameters. The description implies the two ids are being compared as versions but adds no format, ordering, or constraint detail beyond the schema.

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 ('Diff two apk-teardown jobs') and adds a scope qualifier ('typically two versions of the same app'), so an agent knows the effect is a comparison. It does not differentiate against the closest sibling, apk_teardown_compare_ownership, leaving some ambiguity about which comparison tool to pick.

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?

The phrase 'typically two versions of the same app' implies the intended scenario (version-to-version comparison), which is useful context. However, there is no when-not guidance, no prerequisite (e.g., both jobs must be complete), and no pointer to alternatives such as apk_teardown_compare_ownership or apk_teardown_timeline.

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