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

With no annotations, the description carries the full burden and does well: it discloses Stripe test-mode behavior (token reads results only after payment), that mock mode is already paid, that currency is fixed to USD, adaptive pricing is off, and that omitted payer_type defaults to agent. It omits auth/permission requirements and idempotency, keeping it short of a 5.

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 critical behavior and return info is front-loaded, but the fragmentary pricing sentences ("Poll unlock $1. Asker posts $1–$5. Reader unlock $1. Answers are free.") repeat the opener and read as taglines rather than invocation guidance, diluting focus.

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?

No output schema exists, so the description usefully enumerates the return fields and the mode-dependent token behavior. Combined with the payer_type default, an agent has most of what it needs, though the missing when-to-use routing against siblings leaves a gap.

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%, so the description must compensate. It adds meaning for payer_type by stating the default is "agent" when omitted, but gives no explanation of what slug is or what form it takes, leaving the required parameter undocumented in both schema and description.

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 and resource ("Start a $1 poll unlock") and describes the return shape (url, mode, unlock_token), which helps distinguish it from sibling unlock tools. It is clear but not explicitly differentiated from unlock_ask/unlock_poll.

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?

No indication of when to choose this tool over the many sibling unlock/catalog tools. It explains mode behavior but never states the conditions or alternatives under which an agent should call create_checkout rather than unlock_poll or unlock_ask.

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