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

The annotations already declare this is a non-read-only, non-destructive, closed-world operation. The description adds useful behavior beyond that: it returns an upload_url plus headers for PUTting bytes, and the workflow continues via create_drawing. It does not cover URL expiry, auth, or error behavior.

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?

Three compact sentences, front-loaded with the main action and followed by the required next step and the key exception. There is no wasted text.

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 this workflow tool, the description explains the response shape and next call, and the schema already carries limits and enum constraints. It is missing only secondary operational details such as URL expiry, authorization expectations, and failure modes.

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, but it does not explain file_name, content_type, or size. It only implies image upload generally; schema constraints such as the 10 MB maximum and allowed image types are left entirely to the schema.

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: 'Start uploading a picture.' It also distinguishes this tool from create_drawing by describing the two-step upload flow and the upload_id handoff.

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 explicitly says to call create_drawing afterward with the upload_id and that this tool is 'Not needed when the host attaches the picture to create_drawing itself.' That gives both when-to-use and when-not-to-use guidance.

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