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

Annotations already declare destructiveHint=true and readOnlyHint=false. The description's 'Update' is redundant with those annotations and adds no behavioral context such as sparse update behavior, inability to delete, or effects on omitted fields. The schema covers those, but the description itself provides minimal added value beyond the structured metadata.

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 that states the core action and prerequisite without fluff or redundancy. Every word earns its place.

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?

The description is terse, but the overall tool definition is rich: annotations cover destructive behavior and the schema explains all parameter nuances. The agent can correctly invoke the tool by inspecting the schema. The only gap is that the sparse/full update distinction is not in the description, but it is documented in the schema.

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%, with detailed parameter semantics including required Id/SyncToken, prohibited fields, sparse updates, and retirement via Active:false. The tool description only restates the Id/SyncToken requirement, adding no new meaning beyond the schema. Baseline 3 for high schema coverage applies.

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 specifies the action ('Update'), the resource ('class'), and the system ('QuickBooks Online'), and adds the key prerequisite of Id and SyncToken. This distinguishes it from create_class and other update_* siblings.

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 implies use for existing classes ('Update an existing class') but does not explicitly mention when to use it versus create_class, nor that the class must be fetched first (that detail lives in the schema). Usage guidance is left to inference.

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