Get Group Members

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

Beyond the readOnlyHint annotation, the description discloses significant behavioral traits: it is served from a legacy endpoint, may return errors for private groups or migrated surfaces, and the result explains limitations 'honestly'. This adds valuable context about failure modes and data origin that annotations alone do not convey.

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?

The description is exceptionally concise: two sentences that front-load the core purpose and then add relevant caveats. Every word earns its place, with no redundancy or filler.

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?

For a simple tool with only two well-documented parameters and an output schema present, the description covers the essential purpose and behavioral limitations. The combination of annotations, schema, and description leaves little room for confusion.

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 input schema already provides 100% coverage for both parameters (group_id and limit) with descriptions and constraints. The tool description adds no additional parameter-specific explanation, so the baseline score of 3 is appropriate.

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 'List members of a Facebook group' uses a specific verb ('list') and resource ('members of a Facebook group'), clearly distinguishing it from sibling tools like get_group, get_group_posts, or search_groups. It precisely conveys the tool's function without ambiguity.

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 provides clear context by noting it is 'best-effort' and may fail for private groups or migrated surfaces, which helps set expectations. However, it does not explicitly name alternative tools or provide when-not-to-use guidance, so it falls short of a 5.

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