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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds only the team-level scoping as extra context; it says nothing about time-range defaults, how granularity affects aggregation, or how much data comes back.

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?

Two short sentences with zero filler; the resource and scope come first, the trigger condition second. Nothing to trim.

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?

The output schema covers the return shape, but with 0 required params and 0% schema coverage, the agent cannot tell what happens with no dates supplied (all time? default window?) or how granularity interacts with the range. For a stats/aggregation tool these are decisions the caller must get right.

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 0%, so all three parameters (start_date, end_date, granularity) are undocumented except their types and the hourly/daily enum. The description adds no format guidance, no default behavior when dates are omitted, and no note on which granularity applies by default — a real gap for a time-series stats call.

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 and resource ('Returns API key usage statistics') plus the scope ('current user's team'), which is more than a restatement of the title. It does not differentiate from the similar sibling 'get_team_usage', leaving ambiguity about which 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?

Explicitly names the trigger conditions: user asks about API usage, request counts, or rate limits. Clear usage context, but no exclusions or pointers to the near-duplicate alternative 'get_team_usage'.

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