21st_magic_component_refiner

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions that the tool 'returns redesigned version of the component and instructions on how to implement it,' which gives some insight into output behavior. However, it lacks details on permissions, side effects, rate limits, or error handling. For a tool that modifies UI components, this is a significant gap in transparency, as it doesn't clarify if changes are destructive or 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?

The description is appropriately sized and front-loaded, starting with usage guidelines and then stating the purpose. It consists of two sentences that are direct and avoid unnecessary details. However, the first sentence is slightly long and could be more streamlined, but overall, it earns its place by providing clear guidance and purpose without waste.

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?

Given the complexity of a UI refinement tool with no annotations and no output schema, the description is moderately complete. It covers usage and purpose but lacks behavioral details like what 'improves UI' entails operationally, potential impacts, or output format specifics. The absence of annotations and output schema means the description should do more to compensate, but it provides a basic framework that is adequate but with clear gaps for an agent to understand full context.

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 the schema already documents all three parameters thoroughly. The description does not add any additional meaning or context beyond what the schema provides for the parameters. According to the rules, with high schema coverage (>80%), the baseline score is 3 even with no param info in the description, which applies here as the description doesn't compensate or enhance parameter understanding.

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 'improves UI of components and returns redesigned version of the component and instructions on how to implement it,' which specifies the verb (improve/redesign) and resource (UI components). It distinguishes from siblings by mentioning '/ui or /21 commands' and focusing on 'React component or molecule (NOT for big pages),' though it doesn't explicitly name the sibling tools. This makes the purpose clear but not fully differentiated from all alternatives.

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?

The description provides explicit guidance on when to use this tool: 'when the user requests to re-design/refine/improve current UI component with /ui or /21 commands, or when context is about improving, or refining UI for a React component or molecule (NOT for big pages).' It includes specific triggers (commands and context) and exclusions (not for big pages), which clearly defines usage scenarios and helps distinguish from potential alternatives like page-level tools.

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