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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds a meaningful behavioral constraint the annotations do not carry – that the endpoint is gated to paid Veeqo plans – plus a preview of what the payload contains, which helps the agent anticipate a potentially large line-item set.

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 tight fragments with zero boilerplate: payload contents front-loaded, then the plan restriction, then the raw endpoint for API mapping. Nothing is wasted or 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 simple single-id reader with full schema coverage and annotations covering the safety profile, the description is nearly complete: it names the returned entities and the plan gate. It does not mention error behavior for an unknown id or the potential size of the line-item payload, which is the only meaningful remaining gap.

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% with a single parameter ('Veeqo purchase order id' with type and range constraints documented in the schema). The description only restates 'by id' and adds no syntax, format, or boundary detail beyond the schema, so the baseline of 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?

The description gives a specific verb and resource ('One purchase order by id'), states exactly what is bundled into the response ('supplier, destination warehouse and every line item'), and implicitly but clearly distinguishes itself from the sibling list_purchase_orders by restricting to a single id.

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?

The 'Paid Veeqo plans only' eligibility note is useful context, and 'by id' implies use when a specific purchase order id is known. However, there is no explicit when-to-use/when-not guidance and no mention of the list_purchase_orders alternative for when an id is unknown.

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