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

Annotations only cover safety (read-only, idempotent, closed-world). The description adds quota behavior ('Free: it does not count against either allowance'), the auth requirement (sign-in or API key), and the failure mode it prevents (429). That is substantive behavioral context the annotations do not provide.

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?

Front-loaded with the return payload, then the when/when-not guidance, then cost and auth. Five sentences, all of which carry distinct, actionable information; nothing is padding.

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?

There is no output schema, but the description enumerates the returned fields and the reset date, and covers auth and cost. An agent has everything needed to decide whether to call it and what it will get back.

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 are zero parameters, so the schema has nothing to explain and the baseline is 4. The description correctly spends no words on inputs.

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 exactly what the tool returns: total calls and the separate valuation-allowance breakdown (which comps, sold history, trend, flip-score draw down) plus the reset date. No sibling tool covers usage or quota, so it is unambiguously distinguishable from the get_*/search_* family.

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 an explicit use case ('pace a long run instead of hitting a 429 mid-task') and an explicit when-not: 'Every other signed-in tool result already carries the same numbers in `_meta.usage`, so this is rarely needed.' The alternative source of the data is named, not left to inference.

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