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

Reinforces annotations with 'Read-only, no side effects.' Adds that output is JSON with full identity. Could mention the effect of the 'raw' parameter, but overall transparent.

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?

Three concise sentences: purpose, behavior, usage guidelines. No redundancy, front-loaded with key information.

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 simple schema and annotations, description fully covers purpose, output format, side effects, and usage context. References relevant siblings.

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?

Input schema covers the single boolean parameter 'raw' with 100% description coverage. Description does not add context beyond the schema, but baseline is 3 due to high 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?

Clearly states it returns user identity info (UID, GID, username, group memberships) as JSON. Explicitly distinguishes from sibling tools 'whoami' and 'groups', establishing unique purpose.

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?

Provides explicit when-to-use ('comprehensive user identity inspection and access control auditing') and when-not-to-use scenarios with specific alternative tools ('whoami' for quick username, 'groups' for group listing).

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