Reorder a source (z-order)

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

Annotations indicate mutation (readOnlyHint=false) and non-destructive (destructiveHint=false). The description adds meaningful behavioral detail beyond that, such as how 'back' places behind everything, 'front' respects reserved top layers, and the general rule that new sources are added on top. This helps the agent predict 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 description is front-loaded with the core action, then efficiently explains the position options and includes practical examples. Each of the four sentences contributes distinct value, with no wasted words or unnecessary repetition.

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 reorder tool with no output schema, the description fully covers the tool's purpose, parameter behaviors, and typical usage scenarios. It provides enough context for an agent to select and invoke it correctly, including the default scene behavior.

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 coverage is 67% with position lacking a description. The description compensates by explaining the semantic meaning of each enum value ('up', 'down', 'front', 'back') and how they affect z-order. It also clarifies that scene_id defaults to the active scene, adding value beyond the schema.

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 uses a specific verb ('Change') with a clear resource ('source's layer order'), and the title reinforces it as 'Reorder a source (z-order)'. It clearly distinguishes from sibling set_source_* tools by focusing on ordering, not transforms, cropping, or visibility.

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 provides clear when-to-use guidance with concrete examples: using 'back' for backgrounds added after a camera, and notes that alert overlays have a reserved top layer. While it doesn't explicitly name alternative tools for exclusions, the context strongly implies this tool is for z-order manipulation only.

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