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

Adds real context beyond the annotations: one-hour link expiry, safe-to-display semantics, and the fact the customer already received both by email. 'Changes nothing' reinforces readOnlyHint=true and is consistent with idempotentHint=false (fresh links each call). It stops short of describing failure modes for expired or invalid order tokens.

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?

Three short sentences, front-loaded with what is returned, then the expiry caveat, then the read-only reassurance. No 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?

An output schema exists, so return values need no prose explanation; parameters are fully covered by the schema. The description supplies the only non-schema facts an agent needs (expiry, shareability, no mutation).

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% and both parameters are documented there as values returned by start_order, so the baseline of 3 applies. The description adds no additional meaning about order_id or order_token handling.

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: returns download links for the issued certificate and its invoice (PDF). No sibling tool covers certificates, and the scope is unambiguous without opening the schema.

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 clear operational context: the links can be shown to the user, expire after an hour, and should be re-fetched by calling again for fresh ones. It does not name an alternative tool, but none of the siblings are plausible substitutes, so the guidance is sufficient.

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