design_apply_threshold

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

No annotations are supplied, so the description carries the full behavioral burden. It does disclose something useful beyond the name: the result is a new filter *layer* (implying non-destructive application) and that output is binarized to two colors. It does not say which layer/selection the filter targets, whether it is reversible, or how it interacts with existing 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?

A single well-formed sentence with the effect front-loaded and no filler. It is efficient, though the brevity leaves room that could have been spent on targeting or sibling differentiation.

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 4-parameter, zero-required, no-annotation tool with full schema coverage, the description is minimally adequate. It omits where the layer is placed, what it applies to (active layer, selection, whole canvas), and how it relates to the other filter siblings, which an agent would need before invoking it confidently.

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 all four parameters (lowColor, highColor, intensity, threshold) are already documented in the schema with defaults. The description only echoes the color customization idea (black/white vs custom colors) and adds no syntax or range detail beyond the schema. Baseline 3 applies.

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 (add) plus the resource (threshold filter layer) and the visual effect (converts to binary black/white or custom colors). An agent can tell this apart from siblings like design_apply_posterize or design_apply_dither, though the description never names those alternatives explicitly.

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?

There is no guidance on when to choose thresholding versus the many adjacent tonal filters (design_apply_posterize, design_apply_dither, design_apply_duotone, design_adjust_levels, design_adjust_curves). Usage must be inferred entirely from the tool name.

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