Server Quality Checklist

Tool Scores

• create_iphone_mockupA
  4/5.0
  Behavior3/5

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

  No annotations are provided, so the description must convey behavioral traits. It explains cover-fitting of screenshots, the effect of 'bleed' (phone bleeds off bottom), and using 'add_frame' to avoid phone-inside-phone. However, it does not mention whether the tool overwrites output, error handling, or file size limits. The disclosure is adequate but not exhaustive.

  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 a brief introductory sentence followed by a bullet-like Args list. It is concise (about 150 words) and front-loaded with the tool's purpose. Every sentence adds value. Minor inefficiency: the Args section could be more compact, but overall it's clear and readable.

  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 has 10 parameters (5 optional) and an output schema exists, the description is fairly complete. It covers parameter usage, includes a usage guideline for title drafting, and explains key behaviors. It does not discuss return format or error scenarios, but the output schema likely covers that. The description addresses the main purpose and common edge cases.

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

  Parameters5/5

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

  The input schema has 10 parameters with 0% description coverage, so the description must compensate. It does so excellently by describing each parameter in the Args section, including examples for 'size' (valid dimensions), explanation of 'bleed' and 'add_frame' behaviors, and details for 'bg_color' (hex, gradient with comma). This adds significant value beyond the bare schema.

  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 wraps an app screenshot in an iPhone 16 Pro frame with marketing text to produce an App Store-ready preview. It distinguishes from siblings 'create_iphone_mockups_batch' (batch) and 'suggest_themes' (themes) by being a single-image mockup. However, it does not explicitly state when to use this vs the batch variant.

  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 explicit guidance: if the user hasn't dictated the title, the agent should draft one (3-7 words, benefit-led) and get approval before calling. This is a clear usage guideline. It does not specify when not to use the tool or compare to alternatives, but the guidance is actionable.

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

• create_iphone_mockups_batchA
  4.4/5.0
  Behavior4/5

  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 jobs without explicit out path are written to output_dir as NN_<screenshot-name>.png, and lists all parameters and defaults. It does not mention error handling, potential file overwrites, or permissions, but for a file-creating tool, the behavior is reasonably transparent.

  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 well-structured: a one-sentence purpose, followed by workflow guidance, then an Args list. It is concise with no unnecessary words, making it easy for an agent to parse quickly.

  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 that an output schema exists (not shown), the description does not need to explain return values. It covers the main purpose, workflow, parameter defaults, and output behavior. The only minor gap is the undocumented add_frame parameter, but overall it is complete for an agent to use 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 0%, so the description must add meaning. It explains most parameters in the Args section, but the 'add_frame' parameter from the schema is missing from the description. The description adds value over the schema but is not exhaustive.

  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 'Create App Store preview mockups for many screenshots in one call.' It specifies the verb (Create), the resource (App Store preview mockups), and distinguishes itself from siblings by emphasizing batch processing, differentiating from create_iphone_mockup and suggest_themes.

  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?

  Explicit guidance is provided: 'If the user did not dictate the titles, draft one per screenshot... show the user the full list, and get approval or edits before calling this.' This tells the agent when to use and when to seek approval, and implies that for a single mockup, the sibling tool should be used.

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

• suggest_themesA
  4.6/5.0
  Behavior4/5

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

  The description details the process: extracts dominant colors, returns a JSON list with specific fields, orders by recommendation, and chooses text color and frame for contrast. No annotations exist, so the burden is fully on the description, which sufficiently covers the tool's 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 concise (6 sentences), front-loaded with purpose, and each sentence serves a clear role: purpose, usage, outputs, presentation, and argument definition. No unnecessary words.

  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 has a simple input and an output schema (not shown but referenced), the description covers the essential aspects: input format, output structure, and user guidance. It could mention error handling or missing screenshots, but overall it's adequate.

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

  Parameters4/5

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

  The single parameter 'screenshots' is described as 'Absolute paths of the app screenshots to analyze,' which adds meaningful context beyond the schema's bare type definition. Schema coverage is 0%, so this description is essential and effective.

  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 derives background theme suggestions from the app's own colors and distinguishes from sibling tools (create_iphone_mockup, create_iphone_mockups_batch) by emphasizing it should be called first before rendering mockups.

  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?

  Explicitly instructs to call this tool first before any mockups, provides a clear workflow: extract colors, return themes, present list, recommend first entry, offer custom option. This is comprehensive guidance.

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