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

With annotations already indicating mutability and destructiveness, the description adds valuable context: the 20 MB size limit, the full-access permission requirement, and the fact that this action does not create a transaction or transcription. This goes beyond the structured hints without contradicting them.

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 dense but well organized: opening with the core action, then clarifying the three file sources, then constraints, permissions, and exclusions. Every sentence earns its place and no schema information is needlessly repeated.

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 9-parameter mutation tool with no output schema, the description covers the key invocation concerns: what files are accepted, how to supply them, size limits, permissions, and side-effect boundaries. The only minor gap is that it does not describe the call's return value or confirmation behavior.

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 already covers all parameters, so the baseline is 3. The description adds meaningful extra semantics by explaining the three file-source modes: upload_id from the Caribooks document box, file for ChatGPT native descriptors, and content_base64 for small inline bytes. This helps agents choose the right mutually exclusive parameter.

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 states a specific verb and resource: attach a file to an existing QuickBooks transaction, and enumerates supported file types. It also clarifies that it does not create a transaction or render a transcription, which separates it from the create_* family. However, it does not explicitly differentiate itself from the closely named sibling attach_receipt.

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 provides useful context: it targets existing transactions, requires full access, and explicitly excludes creating transactions or rendering transcriptions. It does not name alternative tools such as attach_receipt or state when to prefer them, so the usage guidance is implied rather than explicit.

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