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

Annotations declare readOnlyHint=false and idempotentHint=true, and the description adds real behavioral context beyond them: what payment unlocks (clean PDF, download and delivery options) and the acknowledge_notice sequencing requirement. It never states idempotency itself, but the annotation covers that.

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-loaded with the return value, then prerequisites, then the notices caveat. Dense but every sentence carries information; no obvious filler. The middle clauses are slightly clause-heavy but not wasteful.

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 gated mutation tool with no output schema, it covers the return value, the gating prerequisites, the alternate flow, and the notice edge case. Remaining gaps (expiry, error shapes) are minor and largely outside the tool's core contract.

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 the baseline is 3, but the description goes further by tying acknowledge_notice to the eligibility-notice flow and hinting at delivery options (registered_post). This adds flow meaning on top of the already-documented fields.

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 states a specific verb and resource: it returns a hosted Stripe Checkout URL at the live flat price. That is concrete and distinct from the read-oriented siblings (get_document, get_status), though it never explicitly contrasts itself with a named 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?

It clearly lays out preconditions: the protected draft must be ready and the private review accepted, with a documented exception for report/workspace flows. It stops short of naming any sibling as an alternative, so it is strong context without explicit routing.

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