query_slow_start_rate

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

With no annotations, the description carries the full burden and does disclose meaningful behavior: forced startType grouping, daily-only aggregation, and metric aliases for user-weighted rolling averages. It doesn't cover every possible response edge case, but the key constraints that affect query results are transparently stated.

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 three sentences, front-loaded with the action and resource, and every sentence adds meaningful detail. No filler or repetition of schema 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 query tool with 8 parameters and no output schema, the description handles core domain nuances: metric definitions, forced dimension, API requirements, and aggregation constraints. It gives enough of the row shape via 'slowStartRate plus distinctUsers' and the startType breakdown, though a bit more about response format would push it higher.

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%, so baseline is 3. The description adds value beyond schema by detailing valid metric values (slowStartRate7dUserWeighted, slowStartRate28dUserWeighted) and explaining why startType is a required dimension. This enriches understanding of the metrics and dimensions parameters.

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 clearly states the tool's purpose: 'Query how often the app started slowly' and specifies the exact metrics returned (slowStartRate, distinctUsers). It distinguishes itself from sibling vitals tools by naming the specific metric and the forced startType breakdown.

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 gives actionable usage context: rows are always broken down by startType, the API requires this due to differing thresholds, and users should request slowStartRate7dUserWeighted or slowStartRate28dUserWeighted to match Play Console rolling averages. It does not explicitly name alternatives, but the guidance is clear and specific.

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