run_video_function

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so safety is covered structurally. The description adds genuinely new context by asserting no credits are spent, which is a cost-safety fact absent from the annotations. It does not describe error behavior (e.g., what happens with an invalid payload to validate_request), keeping it below a 5.

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?

Two short sentences, front-loaded with the core action and the function enum, followed by a single negation that prevents the most likely misuse. No wasted wording.

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 dispatcher with a nested params object and no output schema, the description covers purpose, sequencing, and cost safety adequately. The main omission is that it never characterizes what each helper returns, which matters somewhat since there is no output schema to fall back on.

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 100% and the schema already documents all three parameters, including which keys each helper's params object accepts and where identifier/functionName values come from. The description adds no parameter-level detail beyond the function name list, 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?

Names the specific verb (run), the resource (video helper function), and enumerates the three allowed functions (list_input_modes, estimate_cost, validate_request). It also explicitly distinguishes itself from generate_video by stating it does not generate video or spend credits.

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?

"before generation" gives clear temporal context for when to reach for this tool versus generate_video. It stops short of saying which of the three helpers to pick for a given situation, leaving that inference to the function names and the schema's parameter descriptions.

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