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

The annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the tool's non-mutating and safe nature. The description adds the 'by ID' scoping, implying an identifier is required, but it does not disclose error behavior (e.g., 404 on missing order) or return format. Given the annotations provide the core safety profile, a 3 is appropriate: the description adds a small amount of behavioral context without full transparency.

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, front-loaded sentence with no extraneous words, achieving excellent conciseness. However, the extreme brevity omits critical parameter information, so while the structure is clean, the content is insufficient. It earns a 4 for efficiency but loses a point for under-specification.

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 tool that appears to require an order ID, the description fails to specify how to provide it, and the schema is empty. Even though annotations confirm read-only behavior and an output schema exists, the agent lacks the essential parameter detail needed to call the tool correctly. The description is far too thin to be considered complete for this operation.

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?

The input schema is empty, so the description is solely responsible for conveying parameter meaning. It mentions 'by ID', implying a required order ID parameter, but provides no detail on how to pass it (e.g., path, query, body) or its format. With zero parameters defined in the schema and only a vague 'by ID' hint, an agent cannot construct a valid invocation, making parameter semantics inadequate.

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 clearly states a specific verb ('Find') and resource ('purchase order') with a scope ('by ID'), making the tool's purpose understandable. However, it does not differentiate explicitly from sibling tools like getPetById or getUserByName, which follow a similar pattern. The purpose is clear enough for an agent to know what it does, but the lack of parameter detail slightly reduces clarity.

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 guidance on when to use this tool versus alternatives such as getPetById or getInventory. There is no mention of use cases, exclusions, or conditions that would lead an agent to choose this tool over others. This leaves the decision entirely to the agent's inference.

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