design_update_pattern

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

With no annotations, the description carries the full burden. It says 'update' (implying mutation) but discloses nothing about merge-vs-replace semantics for the properties object, what happens when layerId doesn't exist, or whether changes are reversible.

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 front-loaded sentence with no filler. It is efficient, though the brevity reflects under-specification rather than disciplined editing.

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 tool with no annotations and no output schema, the description should cover failure behavior, merge semantics of the nested properties object, and relationship to design_update_layer. None of that is present.

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 (layerId, opacity, visible, properties with JSON-stringify note) are documented in the schema itself. The description adds only the 'by layer ID' framing, which is already in the schema, so the 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 and resource ('Update properties of an existing pattern layer') and identifies the addressing key ('by layer ID'). It is clear on its own, but does not distinguish itself from closely related siblings such as design_update_layer, design_set_pattern_region, or design_set_pattern_shading.

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 use this versus design_update_layer (generic layer update) or the dedicated pattern sibling tools. The agent must infer that this targets pattern layers specifically, with no stated exclusions or alternatives.

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