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

With no annotations, the description carries full burden. It discloses that request_plan 'files a request for super-admin approval — never grants', which is a key behavioral constraint. It also indicates that passing topup_amount or checkout_request_id returns hosted Checkout URLs. No destructive behavior is hidden; mutation is expected for payment actions.

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 sentences, front-loading the main purpose. It efficiently covers the tool's capabilities and parameter behaviors without unnecessary repetition. Slightly long first sentence but overall concise.

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 that the tool has multiple modes (view, request, top-up, complete) and no output schema, the description provides a good overview of return content (status fields, checkout URLs). It could be more explicit about response structure or error handling, but it covers essential information for an agent.

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% with descriptions for each parameter. The description adds context by explaining the overall effect of parameters (e.g., returning hosted checkout URLs) and clarifying that request_plan does not grant or charge. This goes beyond the schema's minimal 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 tool's purpose: 'Billing status + self-service payment' and lists specific items (credit-wallet balance, pay-per-use flag, license tier, etc.). The verb ('get' in name, 'view' in description) and resource are well-defined, and there are no sibling billing tools to confuse.

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 explains when to use the tool: 'Use this to view or RESOLVE a 402 without leaving the connector.' It also provides context for each parameter (checkout_request_id, topup_amount, request_plan) and their effects. It does not explicitly state when not to use it, but the use cases are clear enough for an agent.

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