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

readOnlyHint=true already tells the agent this is a safe read, so the description need not re-assert that. What it does add is meaningful beyond the annotations: the specific sub-resources returned (tasks, taxes, payments) and the invoice URL, which is the only disclosure of return shape given there is no output schema. It does not mention behavior on a missing/invalid id, which is a minor remaining gap.

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, resource scope front-loaded, then endpoint and payload fields. Nothing is padded and nothing crucial is buried.

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 with annotations covering safety and no output schema, the description gives enough to call it correctly and to know what comes back. Only the failure behavior for an unknown id is unaddressed, a small omission rather than a blocking one.

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 the single oid parameter is already documented with its provenance (from hdphotohub_list_orders) and a positive-integer constraint. The description's "by id" adds no syntax or format detail beyond that, so this is the baseline-3 case where the schema does the work.

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?

"Get one order by id" states a specific verb and resource, and the singular scope immediately separates it from the sibling hdphotohub_list_orders. It even enumerates the payload contents (tasks, taxes, payments, invoice URL), so the agent knows what it is retrieving without opening a 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?

There is no explicit "use this when…" or exclusion statement in the description; usage is only implied by "one order" versus the list sibling. The schema's parameter note ("from hdphotohub_list_orders") does quietly encode the intended two-step workflow, but that guidance lives in the schema rather than the description.

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