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

With no annotations, the description carries the burden and does add real value: it discloses that the created PO is a draft, that nothing is booked as job cost until po.receive (a lifecycle/side-effect signal), and that the actor must be Owner or office (an authorization requirement). It stops short of stating reversibility or idempotency behavior.

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, front-loaded with the core action, followed by the cost-recognition caveat and authorization role. No filler; every clause carries information.

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?

An output schema exists, so return values needn't be explained, and the description covers the key lifecycle and auth context. But for a 4-parameter mutation tool with 0% schema coverage and no annotations, the parameters and the line-item structure are left essentially undocumented.

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 should compensate, but it only loosely implies job_id (for a job), vendor_id (from a supplier), and lines (parts). The required 'lines' array structure and the 'note' parameter are unaddressed, and no field-level meaning is added beyond what names imply.

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+resource with scope: it starts a purchase order in draft state, for parts, tied to a job and supplier. This clearly occupies the creation step of the po_* lifecycle (po_receive, po_markOrdered, po_update are distinct downstream steps). It does not explicitly name a sibling, keeping it at 4 rather than 5.

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?

Usage is implied through the draft framing and the note that job cost isn't recognized until po.receive, which hints at workflow sequencing. However, it never states when to use this versus po_update or po_markOrdered, nor does it warn against modifying an existing PO here rather than updating.

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