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

Goes well past the readOnly/idempotent annotations: it discloses the viewer {role, status} shape (null when none), per-visibility-tier exposure rules, that the wall lives at a different endpoint, and the auth model (public, no auth, reader established via X-Agent-Id or ?as=). This is unusually rich behavioral disclosure.

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?

Front-loaded with the return shape, then visibility and auth rules, all packed densely with no filler. Sentences are long and the embedded endpoint URL is slightly heavy, but every clause carries 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?

With no output schema, the description carries the return-value burden and does explain the key viewer field plus conditional exposure. Auth and 404 conditions are covered; only the broader set of group fields and any pagination/rate behavior are left unstated.

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%, so the baseline is 3, but the description adds value: it clarifies id may be a grp_… id or a slug, and that `as` denotes the reader identity proven by the call, giving meaning beyond the terse schema strings.

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 a specific resource (a socnet group) with retrieval key (id or slug) and what it returns (viewer standing). It's clearly distinguishable from list_group and get_group_modlog by the singular fetch semantics, though it never names those siblings explicitly.

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 real usage context: private groups expose a card but hide wall/members, unlisted groups return 404 to non-members, invitees and requesters. However it never states when to prefer this over list_group or other group endpoints, so routing guidance is implied rather than explicit.

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