List a user's groups

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

Annotations already declare readOnlyHint, destructiveHint, and idempotentHint. The description reinforces these and adds return structure details ('JSON array of group objects'). This extra context helps the agent understand what to expect, beyond annotations.

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?

Four short, purposeful sentences, each adding unique value: safety traits, core function, prerequisite, output format. No fluff, front-loaded with key characteristics.

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 simple read-only tool with one parameter and no output schema, the description adequately covers purpose, prerequisite, and return format. It lacks mention of edge cases (e.g., empty list, invalid user ID) but is sufficient for typical usage.

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 coverage is 100% and the description adds no new information about the userId parameter beyond what the schema provides. The hint to resolve the user ID is a usage guideline rather than parameter semantics. 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 the tool lists groups for a user, with explicit mention of being read-only and idempotent. It specifies the output format (JSON array of group objects with id, name, path) and distinguishes from sibling group/user tools by focusing on user-group membership.

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 clear prerequisite guidance: 'Resolve the user ID first with a user listing tool.' This tells the agent when and how to prepare. However, it does not explicitly state when not to use this tool or mention alternatives, so it misses some exclusionary guidance.

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