select_region

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

Does not disclose behavioral traits such as whether it replaces previous selection, affects all tracks, or any side effects, despite no annotations being present.

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?

Extremely concise: two sentences plus an Args block, front-loaded with key purpose, no redundant information.

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?

Lacks information about return value or confirmation of selection; minimal but adequate for a simple state-setting tool.

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?

Adds meaning beyond the schema by specifying units (seconds) for start and end parameters, which the schema's titles lack.

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?

Clearly states that the tool selects a time region in the current track(s) and notes that effects operate on the selection, distinguishing it from sibling selection tools like select_all or select_clip.

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?

Implies usage when wanting to apply effects to a specific region, but no explicit guidance on when not to use or alternatives like select_clip or select_tracks.

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