list_group_members

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

Explicitly states read-only behavior (reinforcing readOnlyHint) and enumerates error conditions: missing resources, invalid identifiers, insufficient permission, and rate limits. This adds useful behavioral context beyond the 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?

Three sentences with the purpose front-loaded. The only minor bloat is a generic reference to project_id when only group_id exists, but it does not significantly distract.

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 the read-only hint, schema, and error disclosure, the description covers what an agent needs to call the tool correctly. Return format isn't described, but no output schema exists and it's a list operation, so this is acceptable.

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 covers all 7 parameters with descriptions (100% coverage), so the baseline is 3. The description adds little new info, only restating that IDs should be provided as numeric or URL-encoded per schema; the query param is already described in the schema.

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 ('List'), a specific resource ('members of a GitLab group'), and mentions optional name/username search. It explicitly contrasts with 'get' tools for single-resource inspection, making it clearly distinguishable from siblings.

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 an explicit usage rule: use for collections, choose the corresponding get tool when you already know the single resource to inspect. This gives clear context, though it does not name a specific sibling tool.

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