comfy_download_batch

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

The description goes beyond the annotations (readOnlyHint=true, idempotentHint=true) by detailing the default behavior (no bytes transfer), the effect of include_size (requires downloading each image), and even discloses a historical bug in the pre-1.5.3 implementation that downloaded full bodies. This is rich behavioral context that helps the agent predict costs and side effects.

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 structured with a summary line, a detailed paragraph, and a bulleted Args section. It includes a historical note that adds transparency but is slightly auxiliary. Overall, it's efficient and front-loaded, with each sentence contributing value.

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?

Given that an output schema exists, return values are already specified. The description covers the tool's purpose, behavior, parameter details, and usage cautions. For a batch metadata lookup with an optional download path, it is fully complete without requiring references to sibling tools.

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 fully carries the burden. It provides an 'Args' section explaining each parameter: filenames as a list, subfolder as optional, and include_size with its default and the implication of downloading. It adds caveats about include_size usage, giving meaningful semantics beyond the bare 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 clearly states the verb and resource: 'Get lightweight metadata for multiple output images.' It explicitly mentions 'multiple' and 'metadata', distinguishing it from single-image retrieval tools like comfy_get_output_image or comfy_list_output_images. The purpose is concise and unambiguous.

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 explains the default metadata-only behavior and cautions that include_size=True downloads each image and 'should only be used for short lists.' While it doesn't explicitly name alternative tools for downloading actual image bytes, the 'no image bytes cross the wire' wording implies that for full downloads, other tools (e.g., comfy_get_output_image) would be appropriate. It provides clear usage context but lacks explicit exclusions.

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