Cancel a pending invitation and immediately invalidate its token; accepted invitations cannot be canceled.
Cancel a pending invitation. The invitation token is immediately invalidated and cannot be used. Cannot cancel invitations that have already been accepted.
| Name | Required | Description | Default |
|---|---|---|---|
| uuid | Yes | Invitation UUID to cancel |
Changes observed during successful MCP inspections.
v1.0.17Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already carry destructiveHint=true, idempotentHint=true and readOnlyHint=false, so the safety profile is covered; the description goes further by disclosing the concrete effect (the token is immediately invalidated and cannot be used) and the precondition that accepted invitations are rejected. It does not say what error or response the caller sees when the invitation is already accepted or not found.
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?
Three short sentences with zero filler; the action and its immediate effect come first and the failure condition last. Every sentence contributes a distinct fact.
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 destructive mutation with no output schema and rich annotations, the description supplies the effect, the irreversibility of the token, and the state precondition. An agent has everything needed to decide whether to call it and to anticipate the rejection case.
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?
Only one parameter, and the schema already describes it fully as 'Invitation UUID to cancel' at 100% coverage. The description adds nothing about the identifier's format or where to obtain it, so the baseline 3 for schema-covered parameters applies.
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 ('Cancel a pending invitation') and scopes it to the pending state, which separates it from invitations_resend and invitations_list in meaning. It stops short of naming a sibling outright, so an agent must infer the boundary from the word 'pending' rather than being told.
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 a clear exclusion: it cannot be used on invitations that have already been accepted, which tells the agent when this call will fail. It never points at the alternative action (invitations_resend) for invitations the user may actually want to re-send instead of cancel.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.