Server Quality Checklist

Tool Scores

• 21st_magic_component_inspirationC
  2.5/5.0
  Behavior2/5

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

  No annotations are provided, so the description carries full burden. It discloses that the tool returns JSON data without generating new code and that the agent must edit files afterward, which adds some behavioral context. However, it lacks details on permissions, rate limits, error handling, or what 'previews' entail. For a tool with no annotations, this is insufficient to fully understand its behavior.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness3/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is three sentences but has redundancy (e.g., repeating 'this tool') and unclear phrasing like '/21st fetch data.' It's front-loaded with purpose but includes an instruction ('After calling this tool...') that might be better placed elsewhere. Some sentences could be more efficient, but it's not overly verbose.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness2/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  Given no annotations, no output schema, and two parameters with full schema coverage, the description is incomplete. It mentions returning JSON data and requiring file edits but doesn't explain the output format, error cases, or how 'previews' are handled. For a tool that involves fetching and post-processing, more context is needed to guide the agent effectively.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters3/5

  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 both parameters ('message' and 'searchQuery'). The description doesn't add any meaning beyond the schema—it doesn't explain how parameters interact or provide usage examples. With high schema coverage, the baseline is 3, as the description doesn't compensate but doesn't detract either.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose3/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description states the tool fetches data and previews from 21st.dev and returns JSON data of matching components, which clarifies its purpose. However, it doesn't clearly differentiate from sibling tools like '21st_magic_component_builder' or '21st_magic_component_refiner'—it mentions 'without generating new code' but doesn't specify how this differs from those siblings. The purpose is somewhat vague regarding the exact scope compared to alternatives.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines2/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The description provides minimal guidance: it says 'Use this tool when the user wants to see component, get inspiration, or /21st fetch data and previews from 21st.dev,' but this is broad and doesn't specify when to choose this over siblings like '21st_magic_component_builder' or 'logo_search.' No explicit alternatives, exclusions, or context for tool selection are given, leaving usage unclear.

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

• 21st_magic_component_refinerB
  3.4/5.0
  Behavior2/5

  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. While it states the tool 'improves UI' and 'returns redesigned version,' it lacks details about how the improvement works (e.g., is it AI-generated, template-based, manual?), what permissions or prerequisites are needed, whether changes are destructive or reversible, or any rate limits. For a tool that modifies UI components with no annotation coverage, this is a significant gap in transparency.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness4/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is appropriately concise with two sentences that directly address usage and purpose. The first sentence efficiently covers when to use the tool, and the second explains what it does. There's no wasted text, though it could be slightly more structured (e.g., separating usage and output more clearly).

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness3/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  Given the complexity (a UI refinement tool with 3 parameters, no annotations, and no output schema), the description is moderately complete. It covers the tool's purpose and usage context adequately but lacks behavioral details (e.g., how refinement works, output format beyond 'redesigned version') and doesn't leverage sibling tool context to differentiate alternatives. Without annotations or output schema, the description should do more to compensate, but it meets a minimum viable level.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters3/5

  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 doesn't add any parameter-specific information beyond what's in the schema (e.g., it doesn't clarify the relationship between 'userMessage' and 'context' or provide examples). With high schema coverage, the baseline is 3, as the description doesn't compensate with additional parameter insights.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose4/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states the tool's purpose: 'improves UI of components and returns redesigned version of the component and instructions on how to implement it.' This specifies both the action (improves UI) and the output (redesigned component + implementation instructions). However, it doesn't explicitly differentiate from sibling tools like '21st_magic_component_builder' or '21st_magic_component_inspiration' beyond mentioning it's for refinement rather than building new components.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines4/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The description provides clear context for 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).' This includes specific triggers (commands) and scope limitations (components/molecules, not big pages). However, it doesn't explicitly mention when to use alternatives like the sibling 'builder' or 'inspiration' tools.

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

• 21st_magic_component_builderA
  3.8/5.0
  Behavior3/5

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

  No annotations are provided, so the description carries the full burden. It discloses key behavioral traits: the tool returns only a text snippet (not integrated code) and requires post-call file editing. However, it lacks details on error handling, rate limits, authentication needs, or what happens if inputs are invalid. For a tool with 5 parameters and no annotations, this leaves gaps in understanding its full behavior.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness4/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is appropriately sized and front-loaded, starting with usage triggers and core functionality. It uses three concise sentences with zero waste, clearly stating purpose, limitation, and required follow-up. However, it could be slightly more structured by separating usage conditions from post-call instructions for better readability.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness3/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  Given the complexity (5 parameters, no annotations, no output schema), the description is partially complete. It covers when to use the tool and its output nature but lacks details on error cases, return format, or how parameters influence the snippet generation. Without an output schema, it should ideally hint at what the snippet contains (e.g., code, documentation), leaving some contextual gaps for effective agent use.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters3/5

  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 5 parameters thoroughly. The description does not add any parameter-specific information beyond what's in the schema (e.g., it doesn't explain how 'searchQuery' relates to '21st.dev' or clarify parameter interactions). With high schema coverage, the baseline is 3, as the description doesn't compensate with extra semantic context.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose4/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states the tool's purpose: to return a text snippet for a UI component when users request new UI components. It specifies the verb 'returns' and resource 'text snippet for that UI component,' and mentions React components as examples. However, it doesn't explicitly differentiate from sibling tools like '21st_magic_component_refiner' or '21st_magic_component_inspiration,' which likely have related but distinct purposes.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines5/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The description provides explicit usage guidelines: 'Use this tool when the user requests a new UI component' and lists specific triggers (e.g., mentions of /ui, /21, /21st, or component names like button, input). It also states 'This tool ONLY returns the text snippet' and instructs on post-call actions ('you must edit or add files to integrate'), clearly outlining when and how to use it versus alternatives like manual coding or other tools.

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

• logo_searchA
  4.1/5.0
  Behavior3/5

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

  With no annotations provided, the description carries the full burden of behavioral disclosure. It describes key behaviors like supporting single/multiple searches, category filtering, theme availability, and result contents, but lacks details on error handling, rate limits, authentication needs, or whether searches are case-sensitive. It adequately covers core functionality but misses operational constraints.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness4/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is well-structured with clear sections (purpose, usage guidelines, examples, format options, result details) and front-loaded key information. It's appropriately sized but could be slightly more concise by integrating some details more tightly, though every sentence adds value without redundancy.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness4/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  Given the tool's moderate complexity, no annotations, and no output schema, the description does a good job covering purpose, usage, parameters, and outputs. It explains what results include (component name, code, import instructions), compensating for the lack of output schema. However, it could better address error cases or limitations to be fully complete.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters3/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  The schema description coverage is 100%, providing full parameter documentation. The description adds minimal value beyond the schema by mentioning category filtering and theme availability, which aren't directly tied to the documented parameters. It doesn't elaborate on parameter semantics like query formatting or format implications, so it meets the baseline for high schema coverage.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states the tool's purpose with specific verbs ('Search and return logos') and resources ('logos in specified format'), distinguishing it from sibling tools focused on component building, inspiration, and refinement rather than logo retrieval. It explicitly identifies the output formats (JSX, TSX, SVG) and search capabilities.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines5/5

  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, including specific triggers like '/logo' commands or requests to add company logos not in the local project. It offers clear examples of valid queries and distinguishes usage scenarios, though it doesn't explicitly mention when NOT to use it or alternatives.

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