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

Annotations only flag destructiveHint=true; the description goes far beyond by explaining state-dependent outcomes (pending stops at once, free; running keeps arrived places and their credits, lets the in-flight search finish, starts nothing new), the prohibition on already-ended collections, and the API key requirement. This is exactly the context an agent needs before invoking a destructive operation.

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?

Front-loads the action and then branches by collection state in a logical order. Mild redundancy between 'costs nothing' and 'Costs no credits', but every sentence carries operative information.

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?

No output schema exists, yet the description covers preconditions, side effects on results and credits, and auth needs thoroughly. It does not indicate what a successful response returns (e.g., final status or confirmation), which is the only notable gap.

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 with 100% schema coverage; the schema already documents id including its provenance from create_collection. The description adds no format or sourcing detail beyond that, so the baseline 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?

States a specific verb (cancel) and resource (collection) and immediately scopes what cancelling means for each state. An agent can distinguish it from siblings like delete_webhook, get_collection, or list_collections without opening any schema.

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 clear conditions for use and a negative condition: a collection that has already ended cannot be cancelled. It does not name an alternative tool for the already-ended case, but no sibling provides that, so the guidance is effectively complete.

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