Stuck background wakelock rate

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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is covered. The description adds meaningful behavioral context beyond annotations: rates are fractions (0.01 = 1%) and output includes 7- and 28-day user-weighted values.

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?

The description is two tightly written sentences. It front-loads the metric identity and source, then adds the essential unit clarification, with no redundant or filler content.

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 read-only metric retrieval tool with full annotation coverage and complete parameter schema descriptions, the description covers the key contextual details: API source, rate units, and aggregation windows. Since no output schema exists, it could say a bit more about the returned data shape, but the essentials are present.

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%, so all four optional parameters (days, filter, dimensions, package_name) are already fully documented in the schema. The description adds no parameter-level meaning beyond what the schema provides, making the baseline 3 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?

The description states a specific metric (stuck background wakelock rate) and its source (Android vitals via Play Developer Reporting API), and it clarifies the units (fractions where 0.01 = 1%). It does not explicitly differentiate from sibling rate tools such as excessive_wakeup_rate, but the metric name itself is sufficiently distinct.

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 description explains what the tool returns but gives no guidance on when to use it versus alternative vitals tools like vitals_summary, vitals_by_version, or other rate tools. There are no exclusions, prerequisites, or routing conditions.

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