select_region

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does not mention that making a new selection replaces any prior selection, that the operation is non-destructive, how the tool handles invalid ranges (end before start), or what state changes occur beyond the selection itself. The minimal prose conveys intent but omits the behavioral context an agent needs to anticipate side effects.

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 purpose sentence is front-loaded and the argument block is tight, with every line earning its place given the 0% schema coverage. The Args section slightly duplicates the schema's parameter names but adds necessary units and meaning, so it is justified. Overall it is efficient with no filler.

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 simple two-parameter tool with no output schema and no annotations, the description covers the core invocation adequately. What is missing is the relationship to the many select* siblings and the behavioral consequence that an effect applied afterward will target this region. These gaps are meaningful for correct tool selection and sequencing, so the description is minimally viable rather than complete.

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 0%, so the description must compensate — and it does by attaching meaning and units to both parameters ('Start time in seconds', 'End time in seconds'), which the schema properties lack. However, it omits constraints such as whether end must be greater than start, whether values are absolute timeline positions, or how out-of-range values are handled. It provides enough to make a plausible call but not full semantic clarity.

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 states a specific verb and resource — 'Select a time region in the current track(s)' — which clearly identifies a timeline-range selection scoped to existing tracks. The time-based nature distinguishes it from track-level siblings like select_tracks and select_clip, though it does not explicitly name those alternatives. Minor deduction because the differentiation relies on inference rather than an explicit contrast.

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 only usage hint is 'Many effects operate on the selection,' which weakly implies this tool is a prerequisite before applying effects. There is no explicit guidance about when to choose select_region versus select_all, select_none, select_tracks, select_clip, select_zero_crossing, or cursor_set_position — a decision the agent must make among many closely related siblings. This is effectively no routing guidance.

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