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

Annotations only indicate readOnlyHint=false and destructiveHint=false. The description adds critical behavioral context: 'Delivery is final and cannot be replaced afterwards, so send the finished thing.' This discloses irreversibility and sets user expectations beyond what the schema or annotations convey.

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 four concise sentences, front-loaded with the core purpose, followed by usage guidance, a parameter hint, and a sibling reference. Every sentence earns its place with no redundancy.

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 tool's moderate complexity (4 params, no output schema), the description covers the action, applicability, exclusions, finality, and how to find pending work. It is complete enough for an agent to select and invoke the tool 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 coverage is 100%, but the description adds a meaningful relationship not present in the field descriptions: 'Pass content, a url, or both.' This clarifies that content and url are alternatives or combinable, which is valuable semantic information beyond the individual parameter descriptions.

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 verb+resource: 'Hand over what a buyer paid for.' It specifies the exact scope (every charge on an on_demand service) and explicitly excludes instant services, distinguishing it from sibling tools like deliver_product and charge_list.

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?

It gives explicit when-to-use ('Use this for every charge on an on_demand service') and when-not-to-use ('instant services deliver themselves at settlement'). It also points to a sibling tool, charge_list, for finding outstanding charges, providing a clear alternative.

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