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

Adds real behavior beyond the annotations: the source file is left unchanged (clarifying that the mutating, non-destructive, non-idempotent operation does not overwrite the original) and that execution is asynchronous and must be polled via get_tool_execution. It stops short of describing failure modes or processing time.

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 short sentences with zero filler: purpose first, then the safety-relevant guarantee, then the async retrieval path. Every sentence earns its place and the most important facts are front-loaded.

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?

An output schema exists, so return-value explanation is not required, yet the description usefully points to get_tool_execution for status and results. Coverage of the input contract and the async lifecycle is adequate, with only the lack of any error/timeout context keeping it from a 5.

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?

Only one parameter and schema description coverage is 100%, so the schema already defines imageFileId and its acceptable sources. The description references the 'source file' only implicitly and adds no format or constraint detail beyond the schema, which is the expected baseline.

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?

States a specific verb and resource ('Create a new image with the background removed'), which cleanly distinguishes it from the sibling remove_video_background and from vectorize_image/upscale_image. An agent can select it without opening the schema.

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 implies the async workflow by stating it returns a toolExecutionId and that get_tool_execution provides status and results, which is genuine usage guidance. However, it never states when to choose this over siblings like remove_video_background or what input images qualify beyond the schema's own note.

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