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

Annotations already declare destructiveHint=true, idempotentHint=true, readOnlyHint=false, so the safety profile is covered. The description adds value beyond them by disclosing the required purchase_orders:write scope and a specific business rule (refusal on lines with received stock), which is exactly the kind of context annotations cannot express.

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: action first, then the permission requirement, then the failure condition. No filler, and the operation itself is front-loaded.

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?

No output schema exists, but for a delete that is acceptable and the annotations carry the destructive semantics. The scope requirement and refusal rule make it nearly complete; only the exact error behavior/side effects of a successful delete are left implicit.

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?

Only one parameter (id) and schema description coverage is 100%, so the schema fully documents the UUID input. The description adds no param-specific meaning beyond the schema, which is the baseline 3 case.

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 ('Delete a purchase order line item'), which cleanly separates it from the create_/update_/get_/list_ purchase order line siblings by naming convention. It does not explicitly name an alternative, but the intent is unambiguous.

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?

Provides a real precondition ('A line with stock received is refused until its quantity_received is set back to 0'), which implies when the call will fail. However, it does not name the alternative tool (e.g., update_purchase_order_line to fix quantity_received) or state when to prefer deletion over other cleanup paths.

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