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

With no annotations, the description carries the full burden and delivers important nuance: the sort order (largest refund-adjusted latest payments first) and the crucial warning that latest_payments is a run-rate, NOT lifetime turnover, plus why no lifetime figure exists. It still omits return shape/pagination and the effect of include_samples, so it falls short of fully self-sufficient.

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?

Front-loaded with the resource and metric, then the caveats, then the sibling routing. Every sentence carries information, though the run-rate explanation could be trimmed slightly.

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 tool with no output schema and no annotations, the metric semantics are well covered, but the include_samples parameter is undocumented and there is no hint of return structure or pagination. Adequate but with a clear gap.

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 single parameter include_samples has 0% schema coverage and is never mentioned in the description, so the agent gets no signal about what it does or when to toggle it. The description compensates well for metric semantics but ignores the one actual input.

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 resource and output scope: a per-app rollup with named metrics (latest_payments/refunded/MRR + paid customer count) in USD cents. It explicitly distinguishes itself from the sibling revenue_summary, so an agent can route without opening a schema.

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 when to use this tool ('compare products at a glance') versus the alternative ('use revenue_summary for one app in depth'). The alternative and its selecting condition are both stated.

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