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

Annotations already convey readOnly, idempotent, and non-destructive behavior. The description adds the 'caller's account' scoping and the REST endpoint mirror, but it does not mention result ordering, pagination behavior, default time window, or whether cost is estimated or final.

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 concise sentences deliver the core purpose and endpoint mapping without waste. The key action and resource are front-loaded, and the mirror reference adds useful context without bloating the text.

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, optional-parameter list tool with a full input schema and an output schema, the description covers the essential context. Minor gaps remain around default date range and when to choose this over similar observability/analytics tools, but these are not critical for invoking 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?

Schema description coverage is 100%, so the parameters start, end, and limit are already documented in the schema. The description adds no parameter-specific meaning beyond framing the resource as usage events, so the baseline 3 is appropriate.

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 a specific verb ('List'), resource ('recent API usage events'), and useful attributes (endpoint, method, status code, cost), scoped to the caller's account. It is unambiguous, though it does not explicitly differentiate from sibling tools like get_analytics or list_observability_events.

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 guidance on when to use this tool versus alternatives such as get_analytics, list_observability_events, or list_tool_execution_logs. The phrase 'Mirrors GET /api/v1/usage' identifies the backing endpoint but provides no selection criteria or exclusions.

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