21st_magic_component_inspiration

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

With no annotations, the description carries the full burden for behavioral disclosure. It states the tool only returns a text snippet, does not generate code, and requires manual integration afterward. However, it is internally inconsistent about 'previews' vs 'only returns the text snippet', and it does not mention no-match behavior, authentication, or data source limitations.

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 reasonably compact but contains redundancy: 'returns the JSON data' vs 'ONLY returns the text snippet' overlap, and the phrase 'or /21st fetch data' is awkward. The final sentence about post-call integration is valuable. Overall, it could be tightened without losing substance.

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 lack of an output schema and annotations, the description covers the tool's purpose, return type, and required follow-up action. It misses a cleaner distinction between 'data/previews' and 'text snippet' and does not mention alternative tools by name, but it is still sufficiently complete for an agent to select and use the tool correctly.

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?

The input schema already provides 100% coverage with clear descriptions for both parameters. The description does not add additional parameter-level semantics beyond what the schema provides, so the baseline score of 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?

The description clearly identifies the tool as a retrieval/inspiration tool for 21st.dev components, explicitly stating it returns JSON/text snippet data and does not generate code. This distinguishes it from sibling tools like the builder, which likely generates components.

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 first sentence gives explicit triggers ('when the user wants to see component, get inspiration, or /21st fetch data'), and the phrase 'without generating new code' provides an exclusion for code-generation use cases. However, it does not name alternative sibling tools explicitly, so it stops short of a full when-not/alternative matrix.

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