Set Preview Input

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

Annotations indicate this is a non-destructive, idempotent write operation (readOnlyHint=false, destructiveHint=false, idempotentHint=true). The description adds value by specifying that it sets the 'preview (next) input,' clarifying it affects the preview bus rather than the program output, and references 'atem_set_program' for input ID consistency. It doesn't contradict annotations and provides useful context beyond them, though it could mention side effects like visual feedback on the switcher.

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 front-loaded with the core purpose in the first sentence, followed by a brief, structured 'Args' section. Every sentence earns its place by clarifying parameters without redundancy. It's appropriately sized for a simple tool, with zero waste, making it highly efficient and easy to scan.

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 moderate complexity (a write operation with two parameters), annotations cover safety and idempotency, and the schema fully describes inputs. The description adds context about the preview bus and input ID consistency. However, without an output schema, it doesn't explain return values (e.g., success confirmation or error details), leaving a minor gap. Overall, it's mostly complete but could benefit from output information.

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 has 100% description coverage, fully documenting both parameters ('input' and 'me') with details like ranges and defaults. The description adds minimal extra meaning, only noting that input IDs are 'same as atem_set_program' and 'me' is optional with a default. This aligns with the baseline score of 3, as the schema does the heavy lifting, and the description provides slight clarification without significant added value.

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 specific action ('Set the preview (next) input') and resource ('on the ATEM switcher'), using a precise verb. It effectively distinguishes this tool from siblings like 'atem_set_program' (which sets the program input) and 'atem_preview_and_auto' (which likely combines preview with auto-transition), making the purpose unambiguous and well-differentiated.

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 implies usage context by referencing 'preview (next) input' and relating input IDs to 'atem_set_program', suggesting it's for configuring the switcher's preview bus. However, it doesn't explicitly state when to use this tool versus alternatives (e.g., 'atem_preview_and_auto' or 'atem_set_program'), nor does it mention prerequisites like needing an active ATEM connection. The guidance is clear but lacks explicit exclusions or named alternatives.

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