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

Annotations already declare readOnly/idempotent/openWorld, so the safety profile is covered. The description adds real value beyond them: the read-scope requirement, the restriction to the authenticated account's memberships, and the dual auth mechanism (Bearer header or key argument). It omits pagination/result-count behavior, which keeps it short of a 5.

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 is correctly front-loaded in the first sentence. However, the credential-retention warning is duplicated almost verbatim in the 'key' schema description, and the auth-mechanism sentence repeats the parameter docs, so the description is longer than it needs to be.

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, a single optional param, and no nested objects, the description covers what an agent needs: purpose, scope requirement, result scoping, and auth. It does not describe return shape or pagination, which leaves a minor gap for a list-style tool.

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?

One optional parameter with 100% schema coverage, so the schema already carries the semantics and baseline is 3. The description restates the auth options for the key argument but adds no new syntax, format, or constraint detail beyond what the schema entry provides.

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 verb and resource ('List private communities this account belongs to') and immediately scopes results to the authenticated account's memberships. It does not name or contrast with siblings like 'community' or 'community_threads', so an agent still has to infer the boundary, but the core purpose is unambiguous.

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?

The description states the prerequisite ('requires read scope') and the result scope, which helps an agent decide if this is the right tool. It never says when NOT to use it or points to a sibling alternative, so usage 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.