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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered; the description adds genuinely new facts — the call is free, never submits payment, and 404 must not be read as proof of non-payment. It stops short of describing what the status/recovery payload looks like, which matters given there is no output schema.

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: purpose first, then the non-mutating guarantee, then the scope caveat. No filler, and the most decision-relevant facts are front-loaded.

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 single-parameter read tool this is close to sufficient, and the 404 caveat is valuable. But with no output schema, the description should say what a successful lookup returns (status fields, recovery details) — that gap is left entirely to inference.

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?

With 100% schema description coverage, the schema already documents orderId as a private client-generated UUIDv4 that must be preserved for retry. The description's "private UUIDv4" phrasing reinforces but does not extend 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?

States a specific verb and resource: a status/recovery lookup for an external Transit order keyed by its private UUIDv4. "Never submits payment" implicitly separates it from the order-submitting sibling via_one_call, though no sibling is named explicitly.

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 conditions for use (status/recovery of an existing external order) and scope exclusions ("Does not cover VIA-owned service receipts"). It also supplies interpretive guidance that a 404 is not proof a payment failed, but does not explicitly name which sibling to call instead for submitting or quoting.

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