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

No annotations are present, so the description must carry the behavioral disclosure burden. It accurately indicates a read-only retrieval operation and specifies the data returned, but it does not mention authentication requirements, potential delays, or any edge cases. For a simple read-only tool, the core behavior is transparent, but richer context would improve the score.

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 a single sentence that immediately states the purpose and the data included. It contains no redundant words, making it both concise and well-structured.

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 with no parameters and no output schema. The description adequately explains what the tool returns (requests used and remaining), which is sufficient for the use case. No additional information is necessary for a complete understanding.

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, and the schema is empty with 100% coverage. The description appropriately avoids adding parameter information since none exist. The baseline for 0-parameter tools is 4, and no deduction is warranted.

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 uses the specific verb 'Retrieves' and identifies the exact resource: the current user's API rate limits, including requests used and remaining. This clearly distinguishes the tool from its siblings (get_courier_rates, get_map_areas), which target different domains.

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 description implies the tool is for checking current API consumption, but it does not explicitly state when to use it or when to prefer an alternative. Since the sibling tools are unrelated, the usage context is clear, but no direct guidance or exclusionary language is provided.

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