update_purchase_order

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

Annotations already declare destructiveHint=true and idempotentHint=true, so the safety profile is covered. The description adds that it 'replaces' item lines, which is consistent with destructive behavior. However, it references 'Same matching/collision caveats as update_sales_order' without explaining what those caveats are, leaving a gap in behavioral disclosure beyond annotations.

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 sentences with no filler. The primary action and key differentiators are front-loaded, and references to sibling tools are concise. Every word earns its place.

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 complex operation with 6 parameters, 5 required, and a nested items array, the description is overly brief and relies on two external references ('Same fields as create_purchase_order' and 'Same matching/collision caveats as update_sales_order') without elaborating. There is no output schema, and the description does not explain return behavior, errors, or prerequisites. An agent cannot fully understand the tool's behavior from this description alone.

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 coverage is 100% with detailed descriptions for every parameter, so the schema already carries the semantic load. The description adds minimal parameter info beyond noting that voucherNumber is the identifier and that fields match create_purchase_order. This is adequate given the schema, but the description does not compensate for any missing context beyond what the schema provides.

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 ('update') and resource ('Purchase Order'), and explicitly says it replaces item lines, party, order number, and narration. Clearly distinguishes from create_purchase_order by noting the extra voucherNumber field, and references update_sales_order for matching caveats, so an agent can tell it apart from siblings.

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?

Implicitly indicates use when updating an existing order (requires voucherNumber) versus creating a new one (create_purchase_order). It mentions 'Same fields as create_purchase_order' and 'plus voucherNumber', which implies that if you have a voucher number you use this tool. However, it does not explicitly enumerate when not to use it or list alternative tools for similar operations.

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