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

With no annotations, the description must carry behavioral burden; it discloses the key precondition (invite must still be pending) but not permissions required, whether the revoked invite can be re-sent, or the failure mode when the invite is no longer pending. That leaves meaningful gaps for a mutation tool.

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?

A single front-loaded sentence with the action first and the constraint second; there is no filler or redundancy.

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 one-parameter mutation with no output schema, the description covers what it does and the critical timing constraint. Only the post-success/error behavior is left unstated, which is a minor gap at this complexity level.

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 is only one parameter and schema coverage is 100%, with the schema already explaining that inviteId comes from the sent invite. The description adds nothing beyond the schema, which is the expected baseline here.

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 pairs a specific verb ('Revoke') with a specific resource ('pending outbound co-signer invite'), so the operation is unambiguous. The qualifiers 'pending' and 'outbound' also distinguish it from accept_cosigner_invite and remove_cosigner, though no sibling is named directly.

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 phrase 'before it is accepted' implies the only valid timing window, which is useful guidance. It does not say what to do instead if the invite was already accepted (e.g., remove_cosigner) or what happens if the ID belongs to an inbound invite.

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