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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds real behavioral context beyond them: the URL is short-lived (1 hour), signed, and requires access to the job. No pagination or error behavior is described, but for a simple read that is minor.

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 tight sentences, front-loaded with the core action and expiry, then routing guidance. The closing clause 'Other tools have no cutout/source assets' duplicates text already in the schema's role description, which is slight redundancy but harms nothing.

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?

The tool is simple (2 params, no output schema), and the description covers what is produced (a short-lived signed URL), the access requirement, and the alternative to use. Nothing needed to call it correctly is missing.

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 100%, so both jobId and role are already documented in the schema, including the enum meanings. The description restates the role options and the access constraint but adds no syntax or format detail beyond that, matching the baseline 3.

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 (mint), resource (signed download URL), the object (background-remover result image with role cutout/source) and the scope (a job the caller can access). An agent can distinguish this from get_file_download_url without opening either 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?

Explicitly names the alternative and the selecting condition: 'Prefer get_file_download_url when the job output already has a fileId.' It also notes that other tools have no cutout/source assets, so the routing decision is fully specified.

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