worker_cancel

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

The readOnlyHint=false annotation already establishes this as a mutating operation, so the bar is lower. The description adds real value beyond that by declaring the effect is 'immediate' and that only workers in the current supervisor session can be targeted. It still omits what happens to in-flight work, whether the cancellation is reversible, and whether the optional reason is recorded or surfaced anywhere.

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?

A single efficient sentence with the urgency qualifier ('Immediately') front-loaded and zero filler. It is well-formed, though its brevity is partly under-specification rather than disciplined economy.

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 mutating tool with zero schema description coverage, no output schema, and only readOnlyHint as an annotation, the description is too thin. It says nothing about what state the worker is left in, whether partial results survive, permission requirements, or the role of the reason parameter.

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 0%, so the description carries the full burden for two parameters, yet it never mentions taskId or reason. 'An active Worker' loosely gestures at taskId, but the optional 500-character reason and its effect are entirely unexplained, leaving the agent to infer both from names alone.

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 states a specific verb pair ('interrupt and cancel') and a scoped resource ('an active Worker owned by the current supervisor session'), which clearly separates it from non-terminating siblings like worker_status or worker_wait. It stops short of naming which sibling to use instead when the goal is correction rather than termination, so it is clear but not explicitly differentiated.

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?

Usage is only implied: the words 'active Worker' and 'owned by the current supervisor session' communicate the precondition that the target must be running and owned by the caller. There is no statement of when not to cancel, no alternative such as worker_steer for course-correction, and no guidance on the optional 'reason' field.

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