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

Discloses that the row is deactivated (not deleted) and historical events remain via recent_alerts, going beyond annotations (readOnlyHint=false, destructiveHint=false) to explain the actual behavior. No contradiction with annotations.

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 sentences, each serving a distinct purpose: action, ownership constraint, and deactivation detail. No unnecessary words.

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 tool's simplicity (one required param, no output schema), the description fully covers behavior, ownership, side effects, and impact on historical data. No gaps.

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 (id) with schema coverage 100%. Description adds no extra info beyond the schema's description ('Subscription id (uuid) returned by subscribe'). Baseline 3 is appropriate as schema already covers the parameter adequately.

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?

Description starts with 'Cancel a subscription by id,' which clearly specifies the verb ('cancel') and resource ('subscription'). It distinguishes from sibling tools like 'subscribe' and 'list_subscriptions' by focusing on cancellation.

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?

States 'Ownership is enforced — you can only cancel your own subscriptions,' providing clear context for when to use the tool (own subscriptions) and implying it should not be used for others' subscriptions. Does not explicitly name alternatives but offers sufficient guidance.

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