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

Annotations already cover safety (readOnly, idempotent, non-destructive, openWorld), so the bar is lower. The description nonetheless adds real behavioral context: results include a previous window for comparison, and all monetary amounts are in cents of the reporting currency — both non-obvious and material to interpreting output.

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?

A single sentence plus a unit caveat, front-loaded with the metric inventory and no filler. Every clause conveys either scope or output semantics.

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?

With no output schema, the description does the necessary work of enumerating what comes back and fixing the unit convention. The remaining gap is how the comparison window is presented in the payload and when this beats sibling analytics tools, but the essentials for calling it correctly are present.

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 100%, with accepted range formats and environment defaults already documented, so the schema carries the parameter burden. The description adds only an indirect hint that the range parameter drives a comparison window; it adds no new syntax or constraints.

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 names a specific resource (revenue) and enumerates the exact metrics returned: MRR, ARR, active/trialing subscriptions, new/expansion/contraction/churn movement, payments and refunds. That enumeration clearly scopes it apart from generic siblings like get_analytics_overview or get_metric_series, though it never explicitly distinguishes itself from them.

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?

There is no when-to-use guidance at all — no statement of which questions this answers versus get_analytics_overview, get_breakdown, or get_timeseries. The agent must infer applicability purely from the metric list, and there are no exclusions or prerequisites (e.g., required app scope) mentioned.

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