List Flow models

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

readOnlyHint=true already tells the agent this is a safe read, so the bar is lower. The description usefully discloses the shape of returned content and clarifies that credit cost means the 'highest tier price', which is real behavioral context. It says nothing about pagination, ordering, or whether the optional filters actually restrict the result set.

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?

One compact sentence with no filler, and the resource is front-loaded. The tradeoff is that it is a noun fragment with no verb, which costs a little clarity in exchange for brevity.

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?

With no output schema, the description correctly carries the burden of describing returned fields, and it does so. However, for a tool with two optional filter parameters it leaves the filtering semantics and result scope unexplained, so an agent cannot fully predict what it will get back.

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 coverage is only 50% (mode has no schema description), and the description compensates by enumerating the mode values (text/references/start_frame/start_end_frames/edit/extend/upsample). That is meaningful information the schema lacks. It does not clarify whether mode/family act as filters or are merely returned fields, so it falls short of a 5.

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 names the resource (video models) and enumerates the attributes each entry carries (key, family, mode, duration, resolution, credit cost), which lets an agent distinguish it from siblings like flow_list_voices or flow_list_projects. It never states the verb explicitly (that it lists/returns these), so the purpose is inferred from the title rather than stated outright.

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?

There is no when-to-use guidance, no mention of the optional mode/family filters as narrowing criteria, and no reference to any alternative tool. The agent must guess whether this is a discovery call, a prerequisite for flow_generate_video, or something else.

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