Icon Composer MCP

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

With no annotations provided, the description carries full burden but provides minimal behavioral context. It mentions only 'solid colors and gradients' despite the enum supporting 'automatic' and 'none' values. No disclosure of mutation semantics, idempotency, side effects, or error conditions.

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?

Two sentences with zero waste. First sentence establishes core purpose, second clarifies capabilities. Front-loaded and appropriately sized for the complexity level.

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?

With 100% schema coverage and no output schema, the description adequately covers the operation concept but has notable gaps. It fails to mention two valid enum values (automatic, none) and provides no behavioral context for a mutation operation (destructiveness, reversibility).

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%, establishing baseline 3. The description adds valuable context that this targets the 'background' fill specifically, distinguishing it from potential layer fills (relevant given 'set_layer_position' sibling). This semantic clarification beyond the schema's 'Path to .icon bundle' warrants a 4.

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 clearly states the tool sets the 'background fill of an .icon bundle' with specific verb and resource. However, it doesn't explicitly differentiate from sibling tools like 'set_appearances' or 'set_glass_effects' which might also affect visual properties.

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 guidance on when to use this versus alternatives, prerequisites (e.g., bundle must exist), or when to choose between fill types. The agent gets no signal about whether this overwrites existing fills or how it interacts with layer-based fills.

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