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

Annotations already signal destructiveHint=true and readOnlyHint=false, so the mutation risk is covered. The description adds the useful prerequisite that Id and SyncToken are required, but it does not disclose the sparse-update semantics or line-replacement behavior—those appear only in the schema. This is adequate but not rich.

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, focused sentence with no filler. It front-loads the action and resource, then states the critical prerequisite.

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?

Although the description is terse, the entity schema is unusually rich and carries the update semantics, sparse behavior, line replacement, and field restrictions. Combined with the destructiveHint annotation, the overall definition gives an agent enough to invoke the tool correctly. The lack of output schema is a minor gap for an update 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?

Schema description coverage is 100%, and the entity parameter's schema already explains Id/SyncToken requirements, sparse updates, line replacement, and PII restrictions. The tool description itself adds no parameter meaning beyond echoing the required Id and SyncToken, so baseline 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 ('Update') and resource ('inventory adjustment in QuickBooks Online'), and the phrase 'existing' plus the prerequisite 'requires Id and SyncToken' clearly distinguishes it from create_inventory_adjustment, delete_inventory_adjustment, and get_inventory_adjustment.

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 makes the usage context clear: updating an already-existing adjustment rather than creating or deleting one. It also states the key prerequisite (Id and SyncToken). It does not explicitly name alternative tools or list exclusion conditions, but the context is sufficient for an agent to select it correctly.

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