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

With no annotations, the description carries the full burden, and it does disclose the non-obvious mid-delivery semantics ("canceled once that attempt ends, unless it succeeds"). It leaves out what happens on an already-delivered task, whether cancellation is reversible, and whether the call is idempotent.

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 tightly written sentences with the primary constraint front-loaded and the exception clause second. No filler, no restatement of the tool name.

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 mutation with no output schema and no annotations, the definition covers the essential precondition and the tricky race condition. Return behavior and the already-delivered error case remain unspecified, which is the only meaningful 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?

Schema coverage is 100% and the task_id description already explains provenance (returned by schedule_http or queue_http) and format. The prose adds no additional meaning about the parameter, so the baseline 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 precondition ("that has not been delivered yet"), which cleanly separates it from sibling mutators like redrive_task or delete_hook. An agent can identify the operation without opening the 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 an explicit applicability condition (task not yet delivered) and clarifies the mid-delivery edge case, which is the main ambiguity an agent would face. It does not name an alternative tool or state what to do if the task is already delivered, so it falls short of full when/when-not routing.

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