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

Annotations already declare readOnlyHint and idempotentHint, and the description adds valuable context by specifying the use of crypto.getRandomValues and the strength of the output. This goes beyond the annotations and helps the agent understand the security characteristics of the tool.

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, front-loaded with the primary action, and contains no unnecessary words. Every phrase adds value, and the structure is highly scannable.

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, the output schema exists, and the description covers the core purpose and security-relevant behavior. Combined with the schema and annotations, it provides sufficient context for an agent to understand and invoke the tool correctly.

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 schema has 100% coverage with clear descriptions for each parameter, so the baseline is 3. The description mentions 'character classes' and 'length' but does not add additional meaning beyond what the schema already provides, making it adequate but not exemplary.

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 cryptographically random passwords and lists the controllable character classes. It is specific and actionable, but it does not explicitly distinguish itself from the sibling 'passphrase-generator' tool, so it falls short of a 5.

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 usage for 'real passwords' and explains that the caller controls length and character classes, providing some context. However, it does not explicitly state when to prefer this tool over alternatives like passphrase-generator, nor does it provide exclusions.

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