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

With no annotations, the description carries the full burden and does so well: it discloses the asynchronous contract ('returns the run id at once — the flow keeps going on eroq's servers'), the billing implication ('each render the flow makes is charged like any generation'), and the plan requirement. This is exactly the behavioral context an agent needs before invoking.

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?

Front-loaded with the action, then prerequisites, parameter guidance, cost, and return semantics in tight succession. No sentence is filler; each carries a distinct fact.

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?

There is no output schema, and the description compensates by explaining the return value (a run id, returned immediately) and how to track the run via get_flow_run. Combined with cost and plan notes, nothing essential for a correct call is missing.

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 the schema already documents all three parameters, including that prompt and image are conditional ('when it asks for a prompt'). The description largely restates this with 'and/or', adding little beyond the structured fields, so the 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 ('Run one of the person's Flows now') and scopes it by naming the plan tier. It also distinguishes itself from the surrounding siblings by pointing to get_flow_run for follow-up and implying list_flows for id lookup.

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?

Gives clear context: name the flow by id or exact name, and supply prompt/image only when the flow requires them, plus a prerequisite (Studio plan and up). It names get_flow_run as the follow-up tool, but does not explicitly state when to prefer this over create_flow/edit_flow.

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