Server Quality Checklist

Tool Scores

• 21st_magic_component_inspirationB
  3.3/5.0
  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. It discloses key behaviors: the tool returns JSON data without generating code, only provides text snippets, and requires post-call file editing. However, it misses details like rate limits, authentication needs, or error handling. It adds value beyond the schema but doesn't fully cover behavioral traits.

  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 front-loaded with the tool's purpose but includes redundant phrasing (e.g., 'This tool returns...' repeated). The sentence about post-call actions ('After calling this tool...') is useful but could be integrated more smoothly. It's moderately concise but has some inefficiencies.

  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 no annotations, no output schema, and 2 parameters with full schema coverage, the description is adequate but incomplete. It covers the tool's purpose and basic behavior but lacks details on output format, error cases, or integration specifics. For a retrieval tool with siblings, it should provide more context on differentiation and usage scenarios.

  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') with clear descriptions. The tool description adds no additional parameter semantics beyond what's in the schema, such as format examples or constraints. Baseline 3 is appropriate as the schema does the heavy lifting.

  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 fetch and return JSON data of matching UI components from 21st.dev for inspiration or previews. It specifies the tool does not generate new code and only returns text snippets. However, it doesn't explicitly differentiate from sibling tools like '21st_magic_component_builder' or '21st_magic_component_refiner' beyond stating it doesn't generate code.

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

  Usage Guidelines3/5

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

  The description provides some usage context: 'when the user wants to see component, get inspiration, or fetch data and previews from 21st.dev.' It implies this is for retrieval rather than creation or refinement, but it doesn't explicitly state when to use this tool versus alternatives like the 'builder' or 'refiner' siblings. The guidance is present but lacks clear differentiation.

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

• 21st_magic_component_refinerA
  3.6/5.0
  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. 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.

  Conciseness4/5

  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.

  Completeness3/5

  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.

  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 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.

  Purpose4/5

  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.

  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: '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.

• 21st_magic_component_builderA
  3.9/5.0
  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 that the tool 'ONLY returns the text snippet' and requires manual integration afterward, which is useful behavioral context. However, it doesn't mention potential limitations like rate limits, authentication needs, error handling, or what format the snippet returns (e.g., React code, plain text). For a tool with 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.

  Conciseness5/5

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

  The description is appropriately sized and front-loaded: it starts with when to use the tool, states its core function, and ends with post-call instructions. Every sentence earns its place—no wasted words. The structure is logical and efficient for an AI agent to parse quickly.

  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 no annotations, no output schema, and 5 parameters (though well-documented in schema), the description is moderately complete. It covers the tool's purpose, usage triggers, and post-call actions, but lacks details on output format, error cases, or integration specifics. For a tool that returns UI snippets, more context on what the snippet contains (e.g., React code, dependencies) would be helpful, but it's adequate as a minimum viable description.

  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 doesn't add any parameter-specific information beyond what's in the schema (e.g., it doesn't explain how 'context' or 'searchQuery' relate to generating the UI snippet). With high schema coverage, the baseline is 3, and the description doesn't compensate with additional param semantics.

  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: 'returns the text snippet for that UI component' when users request new UI components. It provides specific examples of triggers (mentions of /ui, /21, /21st, or component names like button, input, etc.). However, it doesn't explicitly differentiate from sibling tools like '21st_magic_component_refiner' or '21st_magic_component_inspiration' beyond stating this tool 'ONLY returns the text snippet.'

  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' with trigger examples, and states 'This tool ONLY returns the text snippet for that UI component.' It also specifies what to do after calling: 'you must edit or add files to integrate the snippet into the codebase.' This gives clear when-to-use instructions and post-call actions, though it doesn't explicitly mention when NOT to use it or name alternatives.

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

• logo_searchA
  4.3/5.0
  Behavior4/5

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

  With no annotations provided, the description carries full burden and discloses useful behavioral traits beyond basic functionality: it mentions theme support (light/dark), format options with detailed explanations, and return content structure (component name, code, import instructions). It doesn't cover potential limitations like rate limits or authentication needs, but provides substantial operational context.

  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, return details) and front-loaded key information. Some redundancy exists (e.g., repeating format options in different sections), but overall it's efficiently organized with minimal waste.

  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 provides comprehensive context: it covers purpose, usage, parameters, formats, and return structure. The main gap is lack of error handling or edge case information, but it's largely complete 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 baseline is 3. The description adds some value by explaining format options (TSX, JSX, SVG) and providing query examples, but doesn't significantly enhance parameter understanding beyond what the schema already documents with its enum and array descriptions.

  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'), and distinguishes it from sibling tools by focusing exclusively on logo search functionality, unlike component building or refinement tools.

  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 explicitly provides usage guidelines with a dedicated 'When to use this tool' section, listing specific scenarios like '/logo' commands or adding missing logos, and includes example queries to illustrate proper invocation contexts.

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