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

Annotations already declare readOnlyHint and idempotentHint, so the safety profile is covered. The description adds meaningful non-obvious behavior that the annotations do not: the result size and cost are bounded by project size, and large projects may require date-range limiting. This goes beyond a generic read-only claim.

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 long and each sentence earns its place: the first defines what the tool returns, the second places it in the stats tool family, and the third gives performance guidance and the sibling alternative. It is front-loaded with the core purpose and does not repeat 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 read-only drill-down tool with one required parameter and high schema coverage, the description is contextually complete. It explains the breakdown depth, its relationship to the user-level summary, its scalability limits, and the alternative tool to use for more granular data. An agent can correctly select and invoke it from the sibling list without additional clues.

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?

The input schema covers all three parameters with descriptions, including the date format and projectId semantics. The description only adds the advisory that shorter date ranges are useful for large projects, which is a mild addition rather than a deep specification of parameter behavior. This is an appropriately adequate but not rich contribution.

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 returns the full stats breakdown of a single project, and names the exact scope: every Riddle down to blocks, choices, and form fields. It also explicitly links to stats_user_breakdown and stats_riddle_breakdown, so an agent can distinguish it from sibling stats tools without inspecting their schemas.

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 tool's relationship to stats_user_breakdown is spelled out, and concrete guidance is given for when to avoid it or switch to stats_riddle_breakdown on large projects. It also tells the user to prefer shorter date ranges when the project is large, which is actionable operational guidance.

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