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

Annotations already establish readOnlyHint/idempotentHint/non-destructive, but the description adds the state machine that governs this tool and its consequences — most notably that a repeat call with the same idempotency_key executes the purchase, which is exactly the side-effect boundary an agent could otherwise get wrong.

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 sentences, zero filler, and the precondition is front-loaded before the outcome-to-action mapping. The arrow structure makes the decision tree scannable at a glance.

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?

With one parameter, no output schema, and full schema coverage, the description supplies exactly what is missing: the three possible return states and the required follow-up for each. Nothing an agent needs to call and act on this tool correctly is absent.

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 there is only one parameter (ref), whose meaning ('escalation ref from the refusal, esc_…') is already documented in the schema. The description mentions 'the same idempotency_key' and 'the same id', which refer to the execution call rather than this tool's parameter, adding no real meaning beyond the schema. Baseline 3 applies.

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 purpose: reporting whether a person approved a parked payment after an ESCALATION_REQUIRED. It clearly separates this status-check from the sibling execution tool (pay) by describing what to do once approval is granted. It does not name a sibling tool explicitly, so it stops short of a 5.

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 (after ESCALATION_REQUIRED), and each possible outcome carries an unambiguous next action: 'approved' → repeat the call with the same idempotency_key, 'denied' → tell the person and stop, 'pending' → wait and do not repeat. This is a complete when-to-use and what-to-do-next contract.

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