Cancel a task you published

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

Goes well beyond the annotations (readOnlyHint=false, idempotentHint=true, destructiveHint=false) by disclosing the full escrow refund behavior, the auth model (account key via BRICK_BLUE_KEY_FILE, created on first use, backup warning), and that repeating on an already-cancelled task is a no-op. These are non-obvious operational facts an agent needs.

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-loaded with the core action and refund, then routed to usage. Dense and nearly all sentences earn their place, though the key-backup aside is slightly tangential and pushes the length up.

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?

Despite no output schema, the description summarizes the return ('JSON with the task's new state and the refund'), covers the mutation/idempotency behavior, the refund effect, and the auth requirement. Nothing material 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?

Schema coverage is 100% and the single taskId param is already documented ('as publish_task returned it'). The description adds only the scoping semantics ('task you published that nobody has claimed yet'), so baseline 3 applies since the schema carries the parameter detail.

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 ('Withdraws') and resource ('a task you published'), plus the critical scope constraint 'that nobody has claimed yet'. This constraint alone distinguishes it from siblings like fail_task, submit_result, or claim_task 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?

Explicit when-to-use with rationale and an alternative: 'Use it when you no longer need the work or want to repost it with different terms (cancel, then publish_task)'. It also states the when-not case clearly: 'It cannot take back work already claimed or delivered.'

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