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. It usefully discloses that the operation only applies to currently selected tracks and depends on prior selection state. However, it does not state whether this replaces an existing region selection, what happens when no tracks are selected, or whether any track-specific side effects occur.

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 compact, front-loaded with the core purpose, and includes only necessary prerequisite and parameter clarification. Every sentence contributes value, and the Args section is clean and scannable.

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 selection tool with no output schema or annotations, the description covers the essential behavior, prerequisites, and parameter meaning. Minor omissions like exact selection replacement behavior and no-tracks-selected behavior keep it from being fully complete, but nothing critical is missing for a basic call.

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?

The input schema only defines start and end as numbers, with 0% schema description coverage. The description adds real meaning by explaining 'start: Start time in seconds' and 'end: End time in seconds,' including units that the schema omits. It could add constraints like end after start, but the core semantics are adequately covered.

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 opens with 'Select a time region,' a specific verb plus resource, and immediately clarifies that it operates on currently selected tracks, which distinguishes it from sibling selection tools like select_tracks or select_clip. The scope is clearly a time-based selection across tracks rather than a track or clip selection.

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 explicitly tells the agent to call select_tracks or select_all first if needed, which is clear prerequisite guidance. It does not explicitly name alternatives or exclusion conditions, but the dependency and intended invocation context are evident.

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