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

Annotations cover the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false), and the description adds genuinely new behavioral detail: the authorization requirement (owners/admins), plus the failure modes ('not found / not pending / not yours to revoke'). The stated return shape ({'success': True, 'email': ...}) is useful since no output schema exists.

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 and readable, but it carries internal changelog boilerplate ('(2026-07-19: closes the QA-sweep gap where a sent invitation was unremovable from the agent surface.)') that adds no operational value for an agent. That sentence does not earn its place.

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 correctly supplies the return value and error conditions, and it covers the permissions and lifecycle constraint (pending, pre-acceptance). Combined with the annotations, an agent has enough to invoke it correctly.

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 description coverage is 0%, so the description must carry the parameter, and it does: invitation_id is defined as the ID from the user's 'sent' invitations, which disambiguates it from a member or invitee ID. It omits the integer type/format, but for a single required identifier the added meaning is substantial.

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 (revoke/cancel) plus the exact resource and scope: a pending invitation the caller sent, before acceptance. This cleanly distinguishes it from decline_family_invitation (received invites) and list_family_invitations without needing either schema.

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?

Gives concrete when-to-use context ('pending invitation YOU sent', 'before it's accepted', 'sent to the wrong address') and a prerequisite (only group owners/admins can revoke). It does not explicitly name a sibling tool to use instead, but the sent-vs-received framing implicitly routes the agent away from decline/accept.

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