download_output

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

With no annotations, the description must carry behavioral burden; it does add useful environment context ('Requires COMFYUI_HOST') and discloses the format-conversion side effect. It is silent on key write behavior: whether an existing file at dest_path is overwritten, whether missing directories are created, and what happens on failure — significant gaps for a tool that writes to the local filesystem.

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?

Four short sentences, front-loaded with the core action, with prerequisite and environment notes following. Every sentence carries information; a slight tightening is possible but there is no filler.

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 7-parameter filesystem-writing tool with no annotations and no output schema, the description covers the workflow prerequisite and conversion option but omits the return value (does it report the saved path?) and overwrite/error semantics. Adequate, but not complete enough for an agent to predict outcomes on edge cases.

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 every parameter is already documented, including the output_format enum and the convert_quality default. The description only restates the format options ('convert to png, jpeg, or webp') already present in the schema, adding no new meaning. Baseline 3 applies.

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 ('Download a single output file to a local path'), and the word 'single' distinguishes it from the bulk sibling download_all_outputs. However, it does not differentiate itself from download_by_filename, which reads as a near-identical operation, so an agent cannot fully resolve between the two from the description alone.

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?

'Use list_outputs to get file info' gives an explicit prerequisite call, and the note about output_format clarifies the optional conversion path. It lacks exclusions — nothing says when to prefer download_by_filename or download_all_outputs — but the positive usage context is clear and actionable.

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