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

Annotations only say readOnlyHint=false, idempotent, open-world; the description goes far beyond them by disclosing the full payment lifecycle: no charge on call, 'payment_required' status, purchase_id/access_token round-trip, Stripe checkout, 14-day refund, idempotency_key retry behavior, and that CanAIReadMe does not modify the site. This is exactly the behavioral context an agent needs before charging a user.

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?

Purpose and the paid model are front-loaded, and the three paragraphs are tightly organized around purpose, deliverable, and payment flow. Slightly redundant phrasing ('Call it directly in those cases', repeated reassurances about calling never charging) that could be trimmed, but nothing is off-topic.

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?

For a paid, stateful, multi-call tool with an output schema present, the description covers the one thing the schema cannot: the payment-required loop, the privacy of access_token, and how to present the quote to the user. Nothing an agent needs to call this safely is missing.

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%, so baseline is 3, but the description adds real meaning: it clarifies the two-call pattern (first call to get payment_required, second call with purchase_id and access_token to retrieve the package) and that idempotency_key must be a fresh UUID per purchase so retries don't open a second checkout. Minor gap: format's full vs changes_only is left to the schema.

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?

States a specific verb+resource ('Generates the complete, implementation-ready fix') and immediately bounds the scope to AI visibility problems. It names what is delivered (JSON-LD, meta tags, llms.txt) and explicitly contrasts with the sibling audit_ai_visibility, so an agent can pick it without opening a schema.

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?

Gives explicit triggers ('says "fix it" after an audit', 'wants to buy the AI visibility fix'), an explicit alternative for the non-purchase case ('If the user only wants to know what is wrong, use audit_ai_visibility instead'), and exclusions ('Do not use it for general advice or for a site the user has not asked to fix'). Routing is unambiguous.

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