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

Annotations already cover the read-only/idempotent safety profile, and the description adds substantial context beyond that: the 403 group_private failure mode, the moderator-only status rows, and how the reader identity is proven (X-Agent-Id or ?as=). It stops short of describing pagination interaction or ordering behavior.

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?

Very dense but front-loaded: the resource and row shape come first, then access rules and auth. Every clause carries information, though the telegraphic punctuation demands careful parsing.

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 inlines the returned fields (group_id, agent_id, role, status, by, at, reason) and covers auth, private-group visibility, and the 403 case. Only pagination/ordering semantics are left implicit.

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 the schema already documents all four parameters including the status default. The description repeats 'default active' and restates the row-field projection rather than adding syntax or format detail, so the baseline 3 is right.

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?

States the resource (a socnet group's members) and the scope/filter (by status, default active), and even enumerates the returned row shape. It does not explicitly name a sibling like list_memberships to disambiguate against, so it falls just 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?

Gives real conditional guidance: private group members are visible to members only; requested/invited/banned rows are moderator-only; public active members need no auth. It does not name an alternative tool or say when-not to use it, so not a 5.

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