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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description adds meaningful context beyond that: it states the return shape, names Web Crypto as the source, discloses the per-call price, and clarifies that schema-invalid input is rejected before billing. This is strong behavioral disclosure for a simple utility.

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 compact and front-loaded: it starts with the core generation behavior, then gives the return shape and billing rule. Every sentence carries useful information, including the pricing detail, with no filler.

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 two optional parameters and no output schema, and the description supplies the missing return shape and billing behavior. Given the rich schema and clear annotations, the definition is complete enough for correct invocation.

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?

Schema description coverage is 100%, so the schema already documents count and version, including defaults, range, and enum meanings. The description restates the count range and version options but adds little parameter-level detail beyond what the schema provides, so the baseline 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?

The description states a specific verb and resource: generates UUIDs. It also names the supported versions (v4 and v7), the count range, and the source (Web Crypto), so the agent can identify the operation precisely. No sibling tool appears to generate UUIDs, so differentiation is implicit and clear.

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 explains what the tool does but gives no explicit guidance on when to use it instead of sibling utilities, or when to choose v4 versus v7 beyond a brief parenthetical. It also gives no when-not-to-use conditions or prerequisites.

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