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

Annotations already declare read-only, idempotent, non-destructive behavior, so the safety profile is covered. The description adds genuinely useful operational context beyond them: a hard cap of 50 results, the role enumeration including pending, and the caveat that a pending group shows no posts or members yet. Missing only pagination/truncation behavior when more than 50 groups exist.

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?

Purpose and the 50-item cap are front-loaded, then field semantics, then the cross-tool usage hint. Slightly dense and repetitive in places (the 'groups you own/joined/asked to join' clause restates the ownership scope), but every sentence 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?

There is no output schema, so the description must carry the return shape, and it does: the fields (role, members, price), the role values, the 50-item ceiling, and pending-group behavior. An agent can call this and interpret the result without further guessing.

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?

The tool takes zero parameters and the schema is empty, so there is nothing for the description to disambiguate. Baseline 4 applies; the description does not need to compensate for any schema gap.

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 specific resource ("Skool groups of your account") and immediately scopes it to owned/joined/requested groups, which separates it from discovery-oriented siblings like discover_groups and search_group. It also names the fields returned (role, member count, price), so an agent knows this is an account-scoped roster, not a lookup.

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?

Explicitly tells the agent the downstream pattern: "Use group as the group parameter of the other tools," which is real routing guidance. It does not name an alternative for the case where the agent wants to find a group it has not joined (discover_groups/search_group), so exclusion guidance is incomplete.

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