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

Beyond the annotations, it discloses pricing and trial terms, that the human confirms on Stripe and agents never handle cards, that the claim link is one-time and expires in 24 hours, that agentToken must stay private, and that not_found is returned while signups are closed. It could still say more about what happens if start is called for an existing owner, but the payment, secrecy, and failure behavior are well covered.

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?

Front-loads the creation scope, then walks the flow in order: checkout link, human confirmation, claim link, polling, then planner tools. It is dense and reads as a run-on in places, but every sentence carries operational information about the multi-step purchase flow rather than filler.

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 an open-world, non-idempotent tool that kicks off a paid external checkout, the description covers the full lifecycle: what is created, pricing, who confirms, the expiry of the claim link, the recovery path, secret handling, polling until entitled, and the closed-signup error. An output schema exists, so return values need no explanation, and the only real omission is the name parameter.

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 0% for the single `name` parameter, which defaults to "My AI agent" with a length constraint, and the description never mentions it. At low coverage the description is expected to compensate by explaining what the name labels or how it surfaces, and it does not.

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 opening sentence names a specific verb and resource with explicit scope: creates a planner, a private agent token, and a Stripe Checkout link for a person without an account. This distinguishes it clearly from siblings like start_subscription, create_checkout_link, and reissue_claim, which are referenced as downstream steps rather than equivalents.

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 when-to-use (a person without an account), when-not-to-use (not repeatedly, not for an existing owner), and names the alternates for adjacent situations: reissue_claim for a lost link and get_subscription_status for polling entitlement. Little is left to inference.

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