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

Annotations already declare destructiveHint: true, and the description adds no behavioral detail beyond that. The sparse-update behavior, Line array replacement, and DepositToAccountRef requirement are documented in the parameter schema, not the tool description. The description offers no additional context about what happens during the update.

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 sentence that front-loads the purpose and key requirement. It is efficient with zero waste.

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 entity parameter (sparse updates, forbidden fields, line replacement), the tool description alone is insufficient to invoke correctly without reading the schema. However, the schema is comprehensive, and the description covers the most critical precondition (Id and SyncToken). It is minimally complete but leaves key behaviors to 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%, so the baseline is 3. The tool description redundantly mentions Id and SyncToken, which is already in the entity parameter description, adding no new meaning. The rich behavioral details live in the schema, not the description.

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 states a specific verb ('Update'), resource ('existing deposit in QuickBooks Online'), and a critical precondition (requires Id and SyncToken). It clearly distinguishes from create_deposit and delete_deposit by specifying 'existing'.

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 usage for modifying an existing deposit and mentions the need for Id/SyncToken, but it does not explicitly exclude alternatives like create_deposit or mention that you should fetch the deposit first via get_deposit. No when-not-to-use guidance is provided.

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