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

With no annotations provided, the description carries the full burden of behavioral disclosure. It excellently covers idempotency (alreadyCancelled=true), status restrictions, actor attribution (org API key owner recorded per ADR-004), and the distinction from admin cancellation with policy charges—far exceeding typical transparency.

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 front-loaded with the primary action and includes four sentences, each adding critical information (state restrictions, idempotency, flow distinction, actor recording). There is no redundant or filler content; every sentence earns 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?

Given the absence of annotations and output schema, the description is quite thorough, covering status preconditions, idempotency, actor semantics, and the client-flow distinction. However, the complete lack of parameter explanations leaves a notable gap in operation-level context, preventing a perfect score.

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 coverage is 0% for 4 parameters, yet the description gives no explanation of apiKey, orgSlug, sessionId, or cancellationReason. It references the session and org API key conceptually, but does not map these to the actual parameters or clarify their roles, leaving the agent without semantic guidance.

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 clearly states the action: cancel a client's session on behalf of the client. It specifies the resource (client session), the initiating party (cancelledBy=client), and explicitly distinguishes itself from the admin cancellation flow, making its scope unambiguous.

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 explicit when-to-use guidance by listing allowed session statuses (scheduled/pending_confirmation/confirmed) and disallowing past sessions. It also contrasts with the admin cancellation flow, indicating when not to use this tool, which serves as a clear exclusion criterion.

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