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

Annotations indicate destructiveHint=true, and the description implicitly confirms this by describing update semantics. The description adds key behavioral context like sparse vs full updates, which is not in annotations. However, it doesn't discuss authorization requirements or potential side effects beyond the update itself. Since annotations already cover destructiveness, the burden is lower, and the description adds some value but not comprehensive.

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 reasonably concise, one sentence, and gets the essential requirement (Id and SyncToken) early. It doesn't over-explain but also doesn't waste words. It's well-structured.

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 complexity of the update logic (sparse vs full, repeating VendorRef), the description and schema together cover most needed details. No output schema exists, so return format is not explained, but that's not described in the tool description. It might be helpful to note common failure scenarios, but overall it's reasonably complete.

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 schema has 100% coverage, so it already explains the entity and company parameters in detail. The description adds little beyond what the schema provides, leaning mostly on the schema's extensive property descriptions. Baseline 3 is appropriate since schema covers everything.

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 tool description explicitly states it updates an existing vendor credit in QuickBooks Online and requires Id and SyncToken. Since there are many other update tools for different resources, the specific resource (vendor credit) is clear. However, it doesn't explicitly differentiate itself from other update tools, but given the resource name is part of the tool name, that is mostly self-evident.

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 gives clear guidance on the required Id and SyncToken, mentions fetching the VendorCredit first, and warns about sensitive fields to avoid. It also explains the sparse update behavior and the need to repeat VendorRef for sparse updates. It doesn't explicitly say when to not use this tool or what alternative to use, but the guidance is specific and helpful for correct usage.

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