Billing Charges Create

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

Beyond the annotations (readOnlyHint=false, idempotentHint=false, openWorldHint=true), the description adds genuinely useful behavior: the HTTP verb/path and, critically, the required OAuth scope write_charges, which determines whether the call will even authorize. It stops short of saying whether the charge is billed immediately, is immutable, or what a duplicate call does.

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?

Four short lines, front-loaded with the action, then endpoint, scope, and version. Nothing is padded and every line carries operative information an agent needs before calling.

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?

There is no output schema, so the description must carry return-value expectations, and it doesn't say what a created charge returns or how billing/proration works. For a money-moving mutation on an app service this leaves a meaningful gap, though the auth scope and endpoint partially compensate.

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 the schema already documents both parameters; the description only reconfirms service_id as a path segment via 'POST /services/{service_id}/charges'. The 'charge' payload is an opaque anyOf object whose real semantics live in the external Billing API reference, and the description adds no field-level meaning.

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?

Specific verb+resource: 'Create a one-off or usage charge for an app service' tells the agent exactly what is produced and at what scope (app service billing). No sibling tool covers billing charges, so there is nothing to disambiguate against, which caps it just 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 description states the prerequisite ('Required scope: write_charges') and the target surface (app service), which implicitly frames when this applies, but it names no alternative tool and gives no when-not guidance (e.g. subscriptions vs one-off charges, or which sibling billing plan/subscription endpoint to use instead).

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