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

Annotations already declare readOnlyHint=true, so the tool is known to be safe. The description adds behavioral context by explaining randomness (v4) vs. time-sortability (v7), which is useful beyond the annotation's binary safety signal. It also notes the guarantee of correctly formatted output.

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 three concise sentences, front-loading the core purpose and then adding practical usage details. No wasted words; every sentence contributes to understanding the tool's function and selection criteria.

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?

Given the tool's simplicity, an output schema that documents return values, and clear annotations, the description fully covers the essential context: what it does, why it's needed, and how to choose the version. It is complete without being verbose.

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 covers both parameters with clear descriptions and default values, so the description does not need to restate them. The description adds semantic context for the version parameter by explaining when to choose v7, but this is mostly redundant with the schema's enum description. Baseline of 3 is appropriate given full schema coverage.

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 generates UUIDs, a specific and distinct function among the sibling utility tools. It also elaborates on UUID versions (v4 and v7), adding meaningful specificity beyond a simple verb+resource statement.

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 explicitly recommends v7 for database keys and stresses that LLMs cannot produce valid UUIDs, so this tool should always be used. This provides clear when-to-use guidance and effectively excludes manual generation as an alternative.

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