download

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

With no annotations provided, the description carries the full burden and delivers richly: it discloses that a present file proves nothing until status reads 'completed', that 'wait' returns a timeout payload that is NOT a failure, that 'cancel' stops a running transfer and its partial file, and that too-old comfy-cli returns an unsupported error instead of raising. These are exactly the behavioral traits an agent needs to interpret results correctly.

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 dense but every sentence earns its place. The first sentence front-loads the core purpose and the critical negative constraint. The action list is structured as a scannable bullet-like list with clear payload details. No filler or repetition of schema fields.

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 3-parameter tool with no output schema and no annotations, the description covers all essential aspects: what each action returns, the timeout semantics, the required parameter, the error behavior for old comfy-cli, and the caveat about file presence. An agent has everything needed to call the tool correctly and interpret its results.

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 must compensate, and it does. It explains the meaning of action values ('status' default, 'wait' polls, 'cancel' stops), states that download_id is required for every action despite the schema marking it optional with a default, and clarifies that timeout_seconds only applies to 'wait' and is rejected elsewhere. This adds critical meaning 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 opens with a precise verb and resource: 'Track a transfer already started by download_model; does NOT start one.' This immediately distinguishes it from download_model and states the core action. It then enumerates the three action modes (status, wait, cancel) with specific behaviors, making the tool's purpose unmistakable.

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 explicitly says it does NOT start a transfer, which tells the agent when not to use it (when the goal is to initiate a download). It also names the sibling download_model as the tool that starts transfers, and explains the action-specific usage: download_id required for every action, timeout_seconds only for wait and rejected elsewhere. This is explicit when/when-not guidance.

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