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

The description adds context beyond annotations by explaining that the row is deactivated (not deleted) and historical events remain available via recent_alerts. This complements the annotations (destructiveHint=false, idempotentHint=true) and provides full 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?

Two sentences with no wasted words. The first sentence states the action; the second adds critical ownership and data handling details. Information is front-loaded and efficiently conveyed.

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 all essential aspects: action, ownership constraint, and side effects (deactivation vs deletion). It is fully complete given the tool's complexity.

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 100%, with the id parameter fully described as 'Subscription id (uuid) returned by subscribe.' The description adds little beyond repeating 'by id,' so a baseline score of 3 is appropriate.

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 'Cancel a subscription by id,' providing a specific verb and resource. It distinguishes from siblings like subscribe, list_subscriptions, and recent_alerts by describing a cancel operation with ownership enforcement and a soft-delete behavior.

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 explicitly notes ownership enforcement ('you can only cancel your own subscriptions'), guiding when to use the tool. It does not explicitly mention alternatives or prerequisites, but the ownership condition is a clear usage guideline.

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