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

With no annotations provided, the description carries the full burden of transparency. The verb 'retrieves' clearly indicates a read-only operation, and it discloses the output data (requests used and remaining). It also scopes to the current user, adding useful context.

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 two sentences, well-structured, and front-loaded with the primary action. The first sentence states what it does, and the second gives a direct usage suggestion. No unnecessary words or repetition.

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 simple, zero-parameter read-only tool, the description is complete. It explains the resource, the data available, and a use case. It doesn't get into edge cases like errors or authentication, but these are not essential for this straightforward tool.

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 schema is empty. The description doesn't need to explain any parameters, and the baseline for 0-parameter tools is 4. No additional parameter information is necessary.

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 clearly states the tool retrieves API rate limits, specifying the scope ('current user's') and the exact data returned (requests used and remaining). This clearly distinguishes it from sibling tools like generate_tts and get_voices, which are TTS-related.

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 explicitly says 'Use this to monitor your quota,' giving a direct use case. While it doesn't mention exclusions or alternatives, the tool's purpose is simple and unrelated to siblings, so this context suffices.

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