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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, open-world), but the description adds genuinely new behavioral context: a pre-flight re-check of the publication with a hard failure if it changed, and the explicit boundary that the tool 'never pays or signs'. It stops short of describing link lifetime or any auth/permission requirements.

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 short sentences, zero filler, with the core purpose front-loaded and the constraints trailing. Every clause carries information an agent needs.

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?

An output schema exists, so return-value explanation is not required, and the failure mode is disclosed. However, with three undocumented required parameters at 0% schema coverage and no hint of where projectionId or the digest originate, the definition leaves a real gap for an agent trying to call it correctly.

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 all three required parameters, so the description must compensate and largely does not. Only publicationDigest is indirectly illuminated by 're-checks the exact publication'; slug and projectionId (including where projectionId comes from) are never explained in either the schema or the 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?

The description gives a specific verb and resource ('Return an owner-browser checkout link') plus scope ('for one service in a published storefront'), which is far more than the title alone. It does not explicitly route against siblings (voidpay_services/status/storefront), but those cover entirely different domains, so confusion risk is low.

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?

Usage is only implied: you call it to obtain a checkout link, and the sentence 'the server re-checks the exact publication first and fails if it changed' hints that the publication digest must be current. There is no explicit when-to-use, when-not-to-use, or named alternative.

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