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

With no annotations, the description carries the full behavioral burden and does so well: it takes no arguments, does not touch the database, works when other capabilities are degraded, and notes that coverage is narrow and expanding. It also identifies `event_types` as authoritative and warns against trial-and-error boundary discovery.

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 description is front-loaded with purpose and usage, and each sentence adds operational value: when to call, why it is robust, coverage caveats, and how to interpret the response. There is no filler.

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 zero-argument coverage/limits tool with an output schema, the description is complete enough. It explains the tool's behavior, its reliability characteristics, and the semantic importance of `event_types` and `limits` without needing to duplicate the output schema.

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 has zero parameters, so the baseline is 4. The description explicitly notes that it takes no arguments, which is accurate but largely redundant with the empty schema.

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 states a specific verb and resource: it returns what the server covers and the limits it enforces. This is clearly a meta/coverage tool, distinct from the filing and event retrieval siblings, and an agent can identify its role immediately.

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 explicit call timing: call first, or whenever a query comes back empty, to determine whether a filing type is in scope before concluding data is incomplete. It also directs the agent to read `limits` rather than probing for caps.

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