download_image

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

No annotations are provided, leaving the description to carry the full burden of behavioral disclosure. The description notes the tool downloads and optionally crops, but it does not mention side effects (e.g., file overwriting), required permissions, or error behavior if the media_id does not exist. It is a read-style operation, but the lack of explicit behavioral context is a notable gap.

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 a single, front-loaded sentence that names the verb, resource, and key optional behavior. It is concise with no filler, earning a perfect score for conciseness.

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 has 4 parameters, no output schema, and no annotations. The description covers the primary function adequately but does not mention what happens after download, format derivation from out_file extension, or error cases. Given the simplicity of the tool, this is sufficient but not complete—hence a 3.

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 75%, with media_id and out_file already described. The description adds the concept of 'cropping to an exact size,' which clarifies the interplay of size and fit, but the schema already provides substantial parameter detail. The added value is marginal, so the baseline of 3 is appropriate.

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 clearly states the action (download), the resource (image by media id), and adds the optional cropping feature. It distinguishes itself from sibling tools: generate_image creates images, while download_image retrieves existing ones, and flow_status checks status. The phrase 'already exists' reinforces this differentiation.

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 usage context: it applies to images that already exist in Flow, so it should be used after generate_image. It also mentions optional cropping, indicating when the size/fit parameters are relevant. However, it does not explicitly name alternatives or state when not to use the tool, so it falls short of a 5.

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