set_session_region_tool

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

With no annotations, the description carries the full burden of explaining behavior. It discloses the primary effect (highlighting a region) and the optional playback side effect, but it does not clarify whether this replaces the existing selection, whether it moves the playhead, or whether it has any persistent/session-state implications.

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 one tightly worded sentence with the core action front-loaded. It is concise and easy to parse, though it sacrifices explanatory detail for brevity.

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 tool with six parameters, three required, and no annotations, the description is too thin. It does not mention how the parameters relate to each other, what selection_json or query do, or when this tool should be preferred over related session tools.

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, but it only loosely maps to start_sec/end_sec and playing. It does not explain project_path, query, or selection_json, leaving several parameters semantically unexplained.

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 clear verb and resource: 'Highlight a timeline region in the DAW', and mentions an optional side effect of starting browser playback. It is reasonably distinct from many sibling tools, though it does not explicitly differentiate itself from set_session_selection_tool, which may overlap in meaning.

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?

There is no guidance about when to use this tool versus alternatives like set_session_selection_tool or set_session_playing_tool. The description gives a general action but no exclusions, prerequisites, or situational context to help an agent choose among the many session-related siblings.

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