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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds only that this is a single-record lookup by Id, which is useful but not deeply behavioral; it does not mention error behavior or return format, though for a simple read this is acceptable.

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 filler. Every word contributes to the core purpose and retrieval mechanism.

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 get-by-Id operation with fully documented parameters and read-only annotations, the description is nearly complete. It does not describe missing-id behavior, but that is a minor omission for such a well-scoped lookup 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 description coverage is 100%, so the schema already documents both id and company. The description's 'by Id' adds no new meaning beyond what the schema states, so a baseline of 3 is appropriate.

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 uses a specific verb ('Get'), a clear resource ('a single credit memo from QuickBooks Online'), and a retrieval method ('by Id'). It effectively distinguishes itself from sibling search_credit_memos, which is for finding credit memos without requiring a known Id.

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 clearly implies the tool is for retrieving one specific credit memo when an Id is already known. It does not explicitly name alternatives or exclusions, but the 'by Id' wording provides enough context to route the agent appropriately alongside search_credit_memos.

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