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

Annotations already declare readOnlyHint, idempotentHint and non-destructive behavior, so the safety profile is covered. The description adds context beyond that: the metric is verified-only, restricted to Proof Records, and carries no cost ('Free'), which is not encoded anywhere in the structured fields.

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 short sentence with the resource and breakdown dimensions front-loaded and zero filler. Every clause (verified, venue/category/day, Proof Records only, free) adds information an agent can act on.

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 is needed: the metric, the segmentation dimensions and the data scope. A brief note on the aggregation granularity or response shape would close the remaining 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 zero parameters, so there is nothing for the description to disambiguate and the baseline is a 4. The description appropriately spends its words on the return dimensions instead.

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 concrete resource (aggregate agent-job volume) and its breakdown dimensions (venue, category, day), which is far more specific than the title alone. It does not, however, explicitly contrast itself with close siblings such as proof_check, proof_verify_record or agent_records, leaving the agent to infer that this is the aggregate/lookup index rather than the per-record verification path.

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?

The 'Free, read-only' note and '(Proof Records only)' scope imply when this tool is appropriate (a cheap aggregate lookup restricted to Proof Records), but no alternative or exclusion is stated. An agent is left to guess whether volume figures should come from this tool or from ledger_list / agent_records.

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