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

With no annotations, the description carries the full burden, and it does disclose a key trait: 'only creates the checkout handoff and never silently charges the buyer,' which rules out a charge-on-create reading. However it omits other behavioral facts an agent would need, such as whether the URL is returned, URL expiry/reuse, idempotency of repeated calls, and any permission prerequisites.

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?

Two sentences, no waste, and the purpose is front-loaded ahead of the routing guidance. Every clause either states intent or routes the agent to an alternative.

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 3-parameter handoff tool with no output schema, the description covers purpose, the safety-relevant no-silent-charge guarantee, and sibling routing, which is close to sufficient. It would be fully complete with a note on what is returned (the URL) and any auth or expiry constraints.

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 100%, so the enum values (single/top3/full) and the search_id/result_id sources are already fully documented in the schema. The description adds no parameter-level detail beyond that, so the baseline 3 applies.

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?

Specific verb and resource: 'Create a Stripe Checkout URL' after a PaidHandshake search for a buyer authorizing access to locked results. It also distinguishes itself from siblings by naming get_unlock_quote and by excluding recurring watches and machine-wallet jobs.

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?

Explicit when-to-use (buyer wants to authorize access to locked results), when-not-to-use (recurring watches, machine-wallet jobs), and the alternative for the adjacent intent (get_unlock_quote if the buyer only needs pricing). Nothing 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.