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

Annotations already indicate a write operation (readOnlyHint=false) and idempotence. The description adds vital behavioral context beyond annotations: the row is deactivated, not deleted, preserving historical events via recent_alerts. It also explains ownership enforcement. This provides transparency without contradicting any annotation.

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?

Two concise sentences deliver the core purpose and key caveats without any fluff. Each sentence earns its place: first states the action, second covers ownership and the soft-delete behavior.

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 simple one-parameter tool with no output schema, the description covers the operation, a key constraint (ownership), and a behavioral nuance (deactivation not deletion). It doesn't discuss error scenarios or responses, but given the tool's simplicity and the existing annotations, it is sufficiently complete.

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?

The parameter schema already covers the 'id' parameter thoroughly with a description indicating it's a UUID from subscribe. The description adds limited extra parameter semantics (that the subscription must be owned by the caller) but mostly repeats what the schema conveys. Baseline 3 applies due to high schema coverage.

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 subscription by id') and the target resource (subscription). It distinguishes itself from sibling tools like 'subscribe' and 'list_subscriptions' by specifying the cancellation operation and the ID-based approach.

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 offers clear context: ownership enforcement implies you use it only for your own subscriptions, and the deactivation note clarifies the non-destructive effect. It doesn't explicitly name alternatives or exclusions, but the intended usage is obvious given the tool name and siblings.

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