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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=false, destructiveHint=false, so the safety profile is fully covered structurally. The description adds some constraint context (no identities, no raw URL paths, no causal inference) but is disorganized and provides no clarity on freshness limits, rate limits, or what the return actually looks like beyond a fragmentary list.

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?

Three fragmented, comma-spliced utterances with no clear subject or verb. The information is front-loaded but poorly organized and difficult to parse as a coherent instruction.

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 4-parameter tool with nested objects, no output schema, and no annotation guidance, the description is markedly incomplete. It gestures at output shape and privacy constraints but does not provide the parameter or usage information an agent needs to invoke it correctly.

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?

With 0% schema description coverage and 4 parameters (including nested period/comparison objects and an enum breakdown), the description is the only source, yet it mentions only periods, timezone, and filters vaguely. It never explains promotion_id, the breakdown enum values, or the comparison object semantics.

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 describes what the report contains (aggregate metrics, denominators, dates, timezone) but never states a clear verb+resource like 'read promotion performance metrics.' It reads more like a list of output characteristics than a purpose statement, leaving the agent to infer the tool fetches a report from the name alone.

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?

No guidance is given about when to use this tool versus siblings. It never references get_promotion, preview_promotion, get_promotion_schema, or any other tool, so the agent has no routing signal.

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