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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds that a customer email is needed alongside the reference, hinting at an identity-scoped lookup, but it does not say whether the email must match the order's own email or what happens on mismatch.

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?

A single sentence that front-loads the action and names both required inputs with an inline format example. No filler.

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 simple two-parameter read tool this covers invocation adequately, but there is no output schema and no description of what a status lookup returns (status values, order details, error shape), which is the main thing an agent needs to interpret the result.

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 carries the burden, and it does add value: an example reference format ('C-AB-12345') and the clarification that the email is the customer's. It still omits case sensitivity, whitespace handling, and what a mismatched email does, but it compensates meaningfully for the empty schema.

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 and resource ('looks up an existing order') and names both lookup keys, which is enough to distinguish it from create_order and the other siblings. It does not explicitly contrast itself with alternatives, so it falls short of a 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?

'Existing order' implies the precondition that the order must already exist, but there is no explicit when-to-use / when-not-to-use guidance and no mention of what to do when the reference or email doesn't match. Usage is inferable rather than stated.

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