create_purchase_order

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

Annotations cover the safety profile (not read-only, not destructive, not idempotent, closed-world), and the description adds real context beyond them: the result is a draft (not submitted for approval), a preview-confirmation gate is required, and notes are stored verbatim. It doesn't say what the response contains or whether duplicate calls create duplicate POs, but the output schema covers returns.

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?

One front-loaded sentence states the action and the gating requirement, then a compact Args block. Every line adds information an agent needs; nothing is padding.

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 mutation tool with an output schema already present, the description supplies the missing pieces: the draft semantics, the confirmation-code workflow, and full parameter documentation. An agent has everything needed to invoke it correctly without guessing.

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 0%, so the description carries the full burden and does: it documents all six parameters including the nested line-item shape (item_code, qty, rate, optional description), the provenance of supplier and confirmation_code, and an ISO date example for required_by. This is meaning the schema alone does not provide.

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 ('Create a draft purchase order') and the qualifier 'draft' distinguishes it from submit_for_approval and approve_purchase_order in the sibling set. An agent can tell immediately this is the creation step, not the workflow-transition step.

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 an explicit prerequisite and names the alternative: the confirmation code must come from `preview` called with these same args, which establishes the required two-step workflow. It also points to search_suppliers as the source of the supplier ID, so the agent knows the ordering of calls.

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