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

Annotations only say destructiveHint=true and idempotentHint=true; the description explains what that actually means here — a superseding refuted verdict plus a receipted completion_voided ledger event, with the original completion never edited or deleted so hash/receipt chains stay valid. That is exactly the kind of consequence disclosure annotations cannot convey, and 'Full tier' flags a privilege requirement.

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 sentences, zero filler, with the action and the critical 'what is not destroyed' clarification front-loaded. Every clause carries information an agent would otherwise have to guess.

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 mutation with no output schema, the description covers the mechanism, the audit side effect, and the postcondition on the task. Only the 'Full tier' phrase stays opaque rather than specifying the permission or auth requirement.

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?

completion_id is undocumented in the schema, and the description fills that hole precisely by naming its source (tascan_get_task completions[].id). reason's format is left to the schema's 1-500 character description, so only half the parameters get added meaning here.

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 ('Void a completion'), gives the endpoint, and immediately characterizes the target as 'wrong'. That distinguishes it from sibling completion-related tools like tascan_complete_task or tascan_mint_completion_report without naming them.

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?

The trigger condition is explicit: use this when a completion is wrong. It also tells the agent the downstream consequence ('the task reads open again'), which is what an agent needs to decide to invoke it. No exclusions or named alternatives, which is the gap that keeps it from a 5.

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