design_add_mist

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

No annotations exist, so the description carries the full burden. It does disclose meaningful behavior: it creates multiple semi-transparent noise layers with parallax stacking, and that skyColor+colorShift tint back layers only. It omits operational behavior — where the layer is inserted, whether multiple calls stack, determinism via seed, and what is returned.

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?

Four short sentences, front-loaded with the action and visual outcome before the preset list and the v0.2.0 note. The changelog-style version prefix is slightly wasteful but conveys the new parameter pairing efficiently.

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 9-parameter, all-optional layer-creation tool with no annotations and no output schema, the description explains what is produced but not how it fits among the many similar atmosphere tools or what state it mutates. An agent could call it, but could not confidently choose it over design_add_haze or design_add_fog_layer.

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 100%, so the baseline is 3 regardless. The description adds only marginal value: it repeats the preset enum and hints that skyColor and colorShift are used together for atmospheric tint on back layers. It adds nothing about density vs opacity interaction, depthSlot, or layerCount range semantics.

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 gives a specific verb and resource ("Add a mist layer to the design") and describes the visual result: mid-level haze bands with parallax stacking creating depth between terrain ridges. It is immediately distinguishable from unrelated siblings like design_add_sky or design_add_starfield. However, it never distinguishes itself from very close siblings such as design_add_haze, design_add_fog_layer, or design_set_mist_band.

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?

Usage is only implied: the agent can infer this is the tool for mist/haze over landscape depth, but no when-to-use or when-not-to-use statement is made. With three near-identical siblings (design_add_haze, design_add_fog_layer, design_set_mist_band) present, the absence of any routing guidance is a real gap. No prerequisites (e.g., an open sketch/design context) are stated.

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