design_add_fog

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

No annotations are present, so the description carries the behavioral load. It discloses additive behavior, terrain masking, depth stacking, and edge wisps, but omits side effects, whether existing fog is replaced, required terrain context, and return behavior.

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 purpose is front-loaded and the list format is scannable for a 9-parameter tool. However, the preset list largely repeats schema enum values and the 'v0.2.0' version note adds little for tool selection, so it is efficient but not maximally tight.

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 mutation-style tool with no annotations, the description covers purpose and option semantics, and the schema documents most parameters. It still lacks sibling differentiation and side-effect/return context, leaving the agent vulnerable to choosing the wrong fog or atmosphere tool.

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 high at 89%, so the baseline is 3. The description earns more by explaining the fogType meanings ('radiation (calm morning)', 'advection (sea fog)', etc.) and linking presets, adding semantic value beyond the enum values, though several numeric parameters are left to 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 gives a specific verb and resource ('Add a fog layer') and narrows it to 'ground-level fog with terrain masking support', so the agent can tell it creates fog. It does not distinguish this from the sibling design_add_fog_layer or nearby mist/haze tools, so it falls short of a 5.

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?

It lists fog types and presets but never states when to use this tool instead of design_add_fog_layer, design_add_mist, or design_add_haze. No preconditions, exclusions, or alternative-selection guidance are provided, leaving usage to inference.

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