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

With annotations present, the description still adds useful context beyond them: a maximum size, the fact that business records are not changed, the untrusted-data warning, and the target API. However, it does not explain duplicate handling, overwrite behavior, or retention despite idempotentHint=false.

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 key purpose and size limit are front-loaded, and most sentences carry useful information. The documentation pointer and API target are contextually relevant, though slightly administrative relative to the core upload behavior.

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 an upload tool with annotations and an output schema, the description covers purpose, size, safety boundary, and untrusted-data handling. It is not fully complete because it omits duplicate/overwrite semantics and where the uploaded file becomes visible afterward.

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 0%, so the description must compensate. It clarifies allowed general file types and the 8 MiB ceiling, but it does not explain the expected base64 encoding format, filename constraints, or accepted MIME types for the two required parameters.

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 and resource — 'Upload a private document, spreadsheet or image' — and adds scope such as the 8 MiB limit and the connection's workspace. It also distinguishes this upload from business-record mutation by saying 'No business records are changed,' which helps separate it from write-oriented siblings like system_write or system_execute_write.

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?

It gives clear usage contexts: 'for inspection, deterministic import or a later authorized multipart action.' It also implies a boundary by stating no business records are changed, though it does not explicitly name alternatives such as system_stage_attachment or system_stage_file or explain when to prefer them.

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