extend_video

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

With no annotations, the description carries full burden for behavioral disclosure. It only mentions the task creation and return values, but omits important traits like destructive potential, rate limits, authentication needs, or polling behavior (despite 'wait', 'timeout_ms', and 'poll_interval_ms' in the schema). The minimal description offers little beyond the basic action.

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 very concise (single sentence, 14 words) and front-loaded with the main action. However, conciseness comes at the cost of completeness; for a tool with 7 parameters and no annotations, more substance is needed. It is not misleading, but unduly sparse.

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?

Given the tool's complexity (7 parameters, no output schema, no annotations) and the presence of sibling tools, the description is severely incomplete. It does not explain how 'extend_video' relates to 'source_task_id' (likely requires a prior task), nor does it clarify the role of 'output_resolution' or polling parameters. The agent lacks enough context to invoke the tool correctly.

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 low (29%), and the description does not elaborate on any parameters. It fails to explain the meaning or usage of 'prompt', 'source_task_id', 'output_resolution', 'wait', 'timeout_ms', 'poll_interval_ms', or 'model', leaving the agent with little guidance on how to fill the 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 clearly states the action ('Create a Runway task') and resource ('on RunAPI'), and specifies the output ('task id, status, and output URLs'). The parenthetical 'extend video' hints at the specific functionality, but does not fully distinguish from sibling tool 'text_to_video' which also creates a video task.

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 provides no guidance on when to use this tool versus siblings like 'check_pricing' or 'text_to_video'. No prerequisites, typical use cases, or exclusions are mentioned, leaving the agent without context for tool selection.

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