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

With no annotations, the description carries the burden of behavioral disclosure. It reveals that this is a paid operation costing $0.10, that it returns a course id, and that it changes payment economics for subsequent calls. However, it omits information about failure modes, refunds, idempotency, or what happens if payment_tx is invalid.

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 compact and packs cost, workflow, return value, and next steps into two sentences. The wording is telegraphic and could be smoother, but every sentence carries necessary information and the key behavioral constraint is front-loaded.

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?

The core flow is covered: payment, course id, header usage, and zero per-call cost. However, there is no output schema, no details on the HTTP routes to call, no error handling context, and no clarity on whether payment_tx is effectively required despite being unmarked as required.

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 0%, so the description must compensate. It adds meaning by saying 'Pay first, then pass payment_tx,' which explains the temporal dependency and the purpose of the parameter. It does not specify format or where payment_tx comes from, but it provides enough semantic context for the single parameter.

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 identifies a specific action: one payment purchases a course that unlocks five procedures (spa/med/attest/trust-score/seal) and returns a course id. It is not a tautology and clearly distinguishes the course from individual procedure tools, though it does not explicitly name any sibling alternative.

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 gives a clear workflow: pay first, pass payment_tx, obtain a course id, then use it in an X-COURSE header for subsequent calls at zero per-call cost. It does not explicitly state when not to use this tool or name alternatives, but the intended context is clear.

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