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

Annotations declare readOnlyHint=false, idempotentHint=true, and destructiveHint=false; the description adds genuinely non-redundant context on top of that — that the decision is stored with its timestamp, the deciding person, and the proposal, and that nothing is dispatched downstream. It stops short of explaining what 'Keyed' means or what the access_key gate implies for the caller.

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?

Five short sentences, front-loaded with the actor and action, with no filler. The single wasted element is the opening 'Keyed.', which is an unexplained term occupying the highest-attention position.

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 5-parameter mutation with full schema coverage and annotations carrying the safety profile, the description covers actor, resource, persistence, and the key constraint that a human must decide. Only the outcome of the call (what identifier or receipt is returned) is unstated, and with no output schema that is a modest gap rather than a blocking one.

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%, so every parameter including the approved/rejected enum and the access_key is already documented in structured data. The description reinforces the human-attribution requirement but adds no format, validation, or sourcing detail beyond what the schema states. 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?

Names a specific verb pair and resource: a named person approves or rejects a payment intent, with the decision persisted against the time, person, and proposal. That is clear enough to separate it from state-readers like intent_status or approval_status, though it does not explicitly contrast with the closer siblings request_payment_approval and approve_payment_run. The leading fragment 'Keyed.' is unexplained and does not contribute to purpose.

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?

'An agent cannot approve alone' and the required person_name/person_role imply the usage context: this records a human's decision rather than an agent's own. However, it never states when to choose this over request_payment_approval (soliciting) or approve_payment_run (executing), so the agent must infer the ordering. Usage is implied, not spelled out.

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