list_user_groups

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

Annotations already declare readOnlyHint=true, so safety is covered. The description adds genuinely new behavioral context beyond that: it returns full group objects and the result set is paginated, which tells the agent to expect paging behavior and complete group payloads rather than ids.

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 short sentences, zero waste, with the core purpose front-loaded and the prerequisite/routing note last. Every sentence earns its place.

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?

With no output schema, the description usefully covers the return shape ('full group objects with pagination'), which is exactly what an agent needs to interpret results. Only minor omissions remain, such as default page size behavior, which the schema partially covers.

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 skip, page_size and user_id are already documented in the schema. The description only restates that user_id is required and alludes to pagination, adding little beyond the structured fields — the expected baseline of 3.

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 ('List all groups a user belongs to'), and the relational direction ('groups a user belongs to') inherently separates it from the inverse sibling list_group_users. It stops short of explicitly naming list_groups or get_groups as the alternatives an agent might confuse it with.

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?

It gives clear preconditions ('Requires user_id') and routes the agent to list_users to obtain that id. There is no explicit when-not guidance or comparison against sibling group-listing tools, so it falls just short of a 5.

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