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

There are no annotations, so the description carries the full burden. It adds the operational note that it is 'pay-per-use' with a cost, which is useful. However, it does not describe the output format or any edge-case behavior, though the simple generative nature makes this a relatively minor gap.

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 brief and front-loaded, with the core purpose first, followed by contextual and cost information. Every clause earns its place and there is no 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?

For a one-parameter tool with no output schema, the description effectively covers the purpose, the input semantic, and the cost. The return value is clearly implied by 'Generate a regex', so nothing essential is missing.

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 input schema already provides full coverage, describing 'input' as 'qué debe capturar el patrón' (what the pattern should capture). The description's 'input=what to capture' essentially repeats this in English, adding no semnalic richness. With 100% schema coverage, the baseline of 3 is appropriate.

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?

Starts with a specific verb and resource: 'Generate a regex from a description.' This clearly states the tool's function and distinguishes it from the many text-processing sibling tools. It also clarifies the key input requirement.

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 provides context by labeling it a 'High-volume dev tool' and explains that the input should specify what the regex should capture. It does not explicitly state when not to use it or mention alternatives, but none of the siblings directly overlap with a regex generator.

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