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

With no annotations, the description carries the burden and does well: it discloses the write's side effect (creates job-costed materials), asserts it is the sole path to job cost, warns against duplicating with an expense, and states the required role. It omits whether a receipt can be partially reversed, over-receipt limits, and idempotency/duplicate-submit 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 tight sentences, front-loaded with the core action, then the cost behavior, then the default/permission note. No filler and nothing 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?

An output schema exists, so return values needn't be described, and the description covers side effects and defaults well. The gaps are the unexplained `visit_id` parameter and the lack of any note on how to correct a mistaken receipt, which matters for a mutating job-cost tool.

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 0%, so the description must compensate. It explains the most important semantics of `lines` — omit it to receive all remaining quantities — but says nothing about `po_id` beyond the obvious, and never mentions `visit_id` at all, leaving one of three parameters entirely unexplained.

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 concrete verb and resource ('Record parts that arrived') and immediately clarifies the downstream effect (received line becomes a material on the job at that line's cost). This clearly separates it from po_markOrdered, po_recordBill, and po_undoReceipt without needing to open any 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?

Gives a real when-not ('do not also add an expense for it') plus a default-behavior rule ('Leave lines out to receive everything left') and a permission gate ('Owner or office'). It stops short of naming sibling tools like po_undoReceipt for reversing a mistake, so the routing is strong but not exhaustive.

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