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

Annotations already flag destructiveHint=true and readOnlyHint=false, so the safety profile is covered. The description adds the optimistic-concurrency requirement (current SyncToken) and, with no output schema present, tells the agent what comes back ('the saved record with its new SyncToken'), which enables chaining. The specifics of what a destructive sparse update actually clears is left to the schema, not the description.

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?

Two sentences, no waste: the action and its precondition come first, the return value second. Every clause 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?

For a mutation tool with a rich nested schema and annotations already declaring destructiveness, the description covers the prerequisite, the mutation nature, and the return value without an output schema. It omits the top-level warning that updates are sparse and that a Line array replaces all lines, though that detail lives in the entity 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% and the nested entity description already documents Id, SyncToken, sparse semantics, and company resolution in depth. The description's mention of Id and SyncToken repeats schema content rather than adding meaning, so the baseline 3 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?

States a specific verb ('Update') and resource ('an existing deposit in QuickBooks Online'), which is exactly what distinguishes it from the many sibling update_*/delete_deposit/search_deposits tools. An agent can select it without opening the schema.

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?

Gives a clear precondition ('requires Id and the current SyncToken, as the last search or write returned it'), which tells the agent it must retrieve the record first. It does not name an alternative tool (e.g. use search_deposits to fetch the SyncToken) or state when not to use it, so it falls short of a 5.

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