History reach, counts and accepted values

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

Annotations already declare readOnly, idempotent, openWorld and non-destructive behavior. The description adds that the response is a current snapshot and that one call suffices per conversation, but it does not cover auth needs, rate limits, or response format details.

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 the core purpose and then lists distinct returned categories in one dense but waste-free sentence. The short usage note earns its place by preventing redundant calls.

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 zero parameters, no output schema, and annotations covering the safety profile, the description carries the remaining burden well. It enumerates the returned content categories an agent needs to know before calling it.

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 the baseline is 4. The mention of window_days refers to a returned field, not an input, so there is no schema gap to compensate for.

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 reference resource and enumerates exactly what it returns: history window, counts, themes and accepted values. It clearly distinguishes itself from sibling tools that query actual statements, topics, storylines or symbols.

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 says 'One call per conversation is enough,' which gives useful frequency guidance, but it does not explicitly say when to use this versus sibling tools or any prerequisites. Usage is implied by the purpose rather than stated with alternatives.

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