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

Annotations already flag destructive/idempotent/openWorld, but the description adds substantial beyond them: the Human is paid the kill fee, the Budget is held up to paybackLimitCents for 3 days of receipts, non-returned money goes back afterward, the Listing Fee is kept, and remainder returns to the Principal's withdrawable balance. It also discloses the failure mode (fee mismatch → no-op naming the current fee).

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 verb and the key precondition, but the single run-on paragraph buries the money-flow details alongside tangential style instructions (how to phrase the errand to the Principal, writing the id without act_). Dense and hard to scan; some content could be trimmed or split.

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 destructive, open-world mutation with no output schema, it covers timing, money, and failure behavior well. It stops short of describing the response shape beyond 'the answer names the fee now', leaving the success return unclear.

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%, so fields are already documented; the description nonetheless adds meaning by tying killFee to get_act's killFeeCents 'as it shows it now' and by explaining the consequence of a stale value. It says little extra about id, but the schema covers accepted formats.

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 an errand (ACT)') with a precise scope: a Human's claim not yet submitted. It is clearly separable from withdraw_act (removes an unclaimed ACT from the board) and decline_work.

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?

Explicitly instructs to read the ACT with get_act first and pass its killFeeCents as killFee, and states the precondition for success (fee must still match or nothing happens). It also describes the alternative paths once the claim expires (back on the board → withdraw_act, or expires on its own).

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