get_purchase_order

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the agent knows this is a safe read operation. The description adds the scoping detail that it returns a single purchase order, but doesn't describe response shape, error behavior, or any other behavioral traits. It is consistent with annotations, adding minimal but non-contradictory context.

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?

The description is a single, focused sentence of five words, with no filler or redundancy. It is front-loaded with the action and resource, and every word contributes to meaning. For a simple get-by-id tool, this level of conciseness is ideal.

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?

Given the simplicity of the tool (one parameter, strong annotations, no output schema), the description is largely complete. It clearly communicates the core function. However, it lacks any mention of return value expectations or when to use alternatives, leaving a small gap in overall context.

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 100% for the parameter 'purchase_order_id', which is described as 'the id of the purchase order'. The tool description does not add additional meaning to the parameter, so the baseline score of 3 applies since the schema already carries the semantic weight.

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?

The description "Fetch a single purchase order" clearly states the action (fetch), the resource (purchase order), and the scope (single), distinguishing it from list_purchase_orders and other CRUD operations. The verb is specific and aligns with the tool's name.

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?

The description provides no explicit guidance on when to use this tool versus alternatives like list_purchase_orders or search tools. It does not mention prerequisites, exclusions, or alternative selection criteria. The word 'single' only implies a singular result, not usage context.

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