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

Annotations already mark it as a non-read-only, non-destructive write, and the description adds concrete behavioral details: it returns asset_id, enforces a 1 MB request limit (~0.75 MB file), and shows the exact rejection message when the limit is exceeded. It does not contradict annotations.

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 front-loaded and mostly efficient: purpose, return value, usage, and a size caveat. The role instruction is confusing but doesn't bloat the text; every other sentence carries useful information.

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 simple two-parameter upload tool with no output schema, the description covers the return value, the critical size limit, and the main restriction (no barcodes). It falls short on explaining file_name and introduces a phantom parameter, but the core call is still understandable.

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 coverage is 0%, so the description must compensate. It explains the size constraint for image_base64 but says nothing about file_name, and it references a 'role' parameter that is absent from the schema, which is misleading.

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 logo or decorative label background.' It also ties the tool to create_label_design, which distinguishes it from sibling upload tools like upload_customer_logo and upload_item_image.

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 some context ('for create_label_design', 'Do not put a barcode') but does not explicitly compare to alternatives or state when not to use it. The mention of a 'role' is misleading because no such parameter exists in the schema.

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