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

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true, covering the safety profile. The description adds the return content (roles, join dates, status) which is helpful but does not disclose other behavioral traits such as whether the list is ordered, paginated, or scoped to the current user's family group. It adds some value beyond annotations but not substantial context.

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 two sentences and front-loaded with the action and scope. The 'Returns' line clarifies the output, though it partially duplicates the first sentence ('roles and join dates' vs 'role and status info') and introduces a minor inconsistency. Overall it is compact and useful.

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?

Given the tool's simplicity (0 params, no output schema) and annotations covering safety, the description is largely complete. It states what is returned. It could mention prerequisites like family group membership or the absence of filtering, but those are minor given the straightforward nature of the operation.

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?

There are zero parameters and the schema is empty, so per the rubric the baseline is 4. The description doesn't need to explain any parameters. It adds no parameter-specific meaning, but none is required.

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 states a specific verb and resource: 'List all members in your family group with roles and join dates.' This clearly identifies the tool's function. It does not explicitly differentiate from siblings like get_family_group or list_family_invitations, so it falls short of the top score for sibling distinction.

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 no guidance on when to use this tool versus alternatives. It does not mention prerequisites (e.g., must belong to a family group) or exclude cases like viewing invitations or group details. The only implicit hint is the tool name and title, which is insufficient for a clear usage policy.

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