design_add_reflection

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

With no annotations the description carries the full burden, and it does disclose meaningful behavior: the reflection is a fake, built from darkened, ripple-distorted solid color bands, which correctly sets expectations about visual fidelity. It omits other operational facts an agent needs — where in the layer stack the new layer lands, whether an existing water surface is required, and whether repeated calls stack multiple reflection layers.

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?

Three front-loaded sentences: capability, rendering behavior, then the caveat that it is not a real mirror. The trailing preset list largely duplicates the schema enum and is the one part that does not earn its place, keeping this below a 5.

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 an 11-parameter, all-optional layer-creation tool with no annotations and no output schema, the description covers what gets created and how it looks, and the schema covers the parameters. The missing piece is family disambiguation among the many water/reflection siblings, which is exactly the context the description is best positioned to supply.

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 100%, so all eleven parameters already carry descriptions and both enums are defined, which sets the baseline at 3. The description's enumeration of preset names restates the enum rather than adding meaning, and it explains no ranges or interactions for darkening, rippleAmplitude, waterlinePosition, or depthLane.

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?

States a specific verb and resource ('Add a water surface reflection layer') and goes further by explaining what the layer actually renders — solid color bands simulating sky/terrain tones, not a true scene mirror. That distinguishes it conceptually from a generic mirror, but it never differentiates itself from near-identical siblings such as design_add_water_reflection or design_add_water_surface, so an agent cannot pick between them from the text alone.

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?

No when-to-use, when-not-to-use, or prerequisite guidance. The description lists presets but never says whether this should be added after design_add_water_surface, instead of design_add_water_reflection, or how it composes with the water/atmosphere layer tools — all of which are siblings in the same family.

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