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

With no annotations, the description carries the full behavioral burden; it does disclose a genuinely useful trait — a mid-delivery task is only canceled when the attempt ends, and a successful attempt wins. It does not say whether cancellation is irreversible, whether it is idempotent, what happens on an already-delivered task, or what the call returns.

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 short sentences, zero filler, with the core eligibility constraint front-loaded before the edge case. Every clause carries information an agent needs.

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 single-parameter, non-annotated mutation tool with no output schema, the description covers the key precondition and the ambiguous mid-flight case. It could be stronger by noting irreversibility or the expected response, but nothing essential for correct invocation is missing.

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 and schema description coverage is 100%, with the schema already stating the task id comes from schedule_http and enforcing a pattern. The description adds no meaning about task_id beyond the schema, so the baseline of 3 applies.

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 and resource ('Cancel a task') plus the scoping precondition ('that has not been delivered yet'), which is far more informative than the bare name. It does not explicitly differentiate itself from related siblings such as redrive_task or get_task, but the resource and operation are 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?

Gives clear context for use: only tasks that have not yet been delivered, and explains the mid-delivery case. There are no explicit exclusions or named alternatives (e.g. when to redrive instead of cancel), so it stops short of full when/when-not guidance.

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