Icon Composer MCP

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

No annotations are provided, so description carries full burden. It discloses external dependency (Icon Composer.app), underlying tool (ictool), and rendering fidelity (matches iOS 26). Could explicitly state that it writes to filesystem, though 'Render' and output_path schema hint at this.

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?

Three sentences, zero waste: first defines function, second establishes fidelity guarantee, third states critical prerequisite. Front-loaded with essential information.

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 15-parameter rendering tool with no output schema, description covers prerequisites, external dependencies, and rendering behavior adequately. The schema documents output format (PNG), so the absence of output schema is mitigated.

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 has 100% coverage with excellent detail (e.g., light_angle controls 'specular highlights'). Description adds semantic cohesion by framing all parameters as serving 'Liquid Glass' rendering, helping the agent understand why parameters like tint_color and glass effects exist together.

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?

Excellent specificity: verb 'Render', resource 'Liquid Glass preview', technology 'Apple's ictool', and fidelity claim 'exact same rendering as iOS 26'. Clearly distinguishes from sibling export_preview by focusing on Liquid Glass effects and ictool integration.

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?

States prerequisite 'Requires Icon Composer.app installed' but lacks explicit guidance on when to use this vs sibling tools (e.g., export_preview) or when-not-to-use. Usage must be inferred from the Liquid Glass specificity.

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