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

With no annotations, the description carries the full burden. It discloses a key behavioral trait: gifts expire after seven days while payables do not, which helps the agent choose the correct kind. However, it does not mention other side effects such as whether funds are deducted immediately, what happens on failure, or whether the offer is immediately visible. This is partial disclosure.

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?

The description is two short sentences with no filler. The primary purpose is stated first, and the expiry distinction follows immediately. Every word contributes meaning, and it is well-structured.

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?

Given the nested object, required idempotencyKey, no annotations, and no output schema, the description is too brief. It does not specify how to indicate a payable versus a gift (e.g., the 'kind' field values), what the idempotency key is for, or what a successful response looks like. An agent would struggle to invoke this correctly without additional documentation.

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 0%, so the description must compensate, but it only hints at the 'kind' parameter via 'gift or payable'. It does not explain 'amount', 'reason', 'targetAgentId', 'idempotencyKey', or other fields. The description adds minimal value beyond what the schema already exposes (which is just field names and types). An agent would be uncertain about how to fill the nested object correctly.

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 clearly states the action: 'Reserve earned credits for a gift or already-earned payable.' It specifies the resource (earned credits) and the two purposes. It is not a tautology and distinguishes between gift and payable, though it doesn't explicitly contrast with sibling tools like accept_offer or decline_offer.

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 description provides implicit usage context by explaining the difference between gifts and payables, but it does not explicitly state when to use this tool versus alternatives such as accept_offer, decline_offer, or list_offers. No explicit when-not guidance is given, so an agent must infer that creation is the intent from the verb 'create' and the sibling names.

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