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

Annotations already declare destructiveHint=true, and the description reinforces this with an up-front 'DESTRUCTIVE' marker while adding real value the annotations do not carry: the settlement-state precondition and the required ID form. It stops short of describing irreversibility nuances or failure modes, so not a 5.

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?

Three compact sentences, all front-loaded: hazard warning first, then the eligibility condition, then the alternative. Every clause earns its place with no filler.

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 one-parameter mutation with destructiveHint coverage and no output schema, the definition supplies everything needed: the safety profile, the precondition, the ID format, and the sibling routing. Nothing required 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 description coverage is 100% and the single parameter is fully documented there; the description's 'Use the GraphQL global transaction ID' only restates the schema's 'GraphQL global transaction ID to void.' Per the baseline rule for high coverage, a 3 is appropriate.

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/cancel a transaction) plus the critical scope constraint (has NOT yet settled), which separates it cleanly from the sibling refund tool. It also names the underlying GraphQL mutation, so an agent knows exactly what operation it is.

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 states both when to use it (unsSettled authorization or submitted-for-settlement transaction) and when not to (already-settled), naming braintree_refund_transaction as the alternative for that case. Nothing is left to inference.

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