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

Annotations only declare the safe read profile; the description adds the operationally decisive facts an agent cannot infer: the endpoint is exempt from every metering stage, so it consumes no hourly call, concurrency slot, or credit. It further discloses that ceilings are per-plan and change without a release, which explains why the values are authoritative and volatile.

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?

The core claim is front-loaded in the first clause, followed by three short paragraphs that each carry distinct information: what is answered, what it costs, and when to call it. No sentence restates the schema or the annotations, and the rhetorical opener still conveys the key property (non-metered introspection).

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?

The tool is simple (zero required params) and an output schema exists, so return values need no prose explanation. What an agent still needs in order to call it well — cost model, volatility of the ceilings, and error-recovery usage — is all 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?

There is a single optional `response_format` parameter and the schema already documents both enum values at 100% coverage, so the schema carries the full burden. The description adds no syntax or format guidance beyond that, which is the baseline case rather than a gap.

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 verb and resource — reporting the caller's current entitlements — and enumerates exactly what is reported: remaining searches this hour, plan history depth, max `limit`, concurrency, and retry wait. It explicitly positions itself against siblings by saying it answers what the `news` tool descriptions cannot, so an agent can distinguish it from `check_coverage`, `check_health`, and `get_story` 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?

It gives two concrete trigger conditions — before planning a batch of calls, and after any plan-limit or rate-limit error — and explicitly says to prefer it over numbers hard-coded in other tool descriptions. That is a named alternative plus the condition that selects it, which is the routing guidance the dimension asks for.

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