coverage

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

Annotations already declare readOnly, idempotent, non-destructive, so the safety profile is covered. The description adds genuinely non-structured context: the call is free (no record credits) and that the response surfaces data limitations, which an agent needs to interpret results.

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, front-loading what is returned before the cost note. Nothing is repeated from the annotations or schema.

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 parameters, no output schema, and full annotation coverage, the description supplies what the agent needs: the three kinds of information returned plus the zero-cost property. Only the shape of the 'data limitations' output is unstated, a minor 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 tool takes no parameters, so the baseline is 4; there is nothing for the description to disambiguate. It correctly makes no attempt to describe argument 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?

States a specific verb ('Get') and the concrete payload: release date, catalog coverage, and data limitations. The name 'coverage' alone is ambiguous, but the description resolves it; sibling differentiation is only partial, relying on the implicit contrast between a metadata call and record-consuming calls like unlock_records.

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 record credits spent' hints at when to prefer this over credit-consuming siblings such as unlock_records or preview_records, but the connection is left to inference. There is no explicit 'call this before/after X' or stated exclusion.

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