Server Quality Checklist

Tool Scores

• compare_imagesA
  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 describes pixel-by-pixel comparison and output, but does not mention constraints like same dimensions required, or error cases. Could be more explicit about limitations.

  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?

  Two sentences, front-loaded, no redundant information. Every sentence adds value: purpose, supported formats, and output description.

  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?

  No output schema exists, but the description explains the return values (different pixels, percentage, diff image). It also covers supported formats. Missing potential details like image size requirements, but overall adequate for a tool with well-documented parameters.

  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 baseline is 3. The description does not add extra meaning beyond the schema for parameters like threshold or includeAA, which are already well-documented in the schema.

  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 uses a specific verb ('Compare two local image files'), identifies the resource type, and distinguishes from siblings by specifying 'local image files' while siblings likely handle URLs. It also mentions supported formats and output.

  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 implies usage for local files but does not explicitly state when to use this tool versus the sibling tools (compare_image_with_url, compare_urls). No prerequisites or exclusions are mentioned.

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

• compare_urlsA
  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 full disclosure burden. It mentions capturing screenshots and pixel-by-pixel comparison, but does not address potential issues like dynamic content, network timeouts, or resolution 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?

  Two sentences convey purpose and output clearly. No unnecessary words, highly efficient.

  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?

  For a 5-parameter tool with no output schema, the description explains the return type (difference statistics and diff image) sufficiently. However, it could be more specific about the statistics format (e.g., percentage difference) given the lack of output schema.

  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 coverage is 100%, so baseline is 3. The description adds high-level context but does not elaborate on parameter semantics beyond what the schema already provides. The threshold and includeAA parameters are adequately described in the schema.

  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 explicitly states the verb 'compare' and resource 'screenshots from two URLs' and distinguishes from sibling tools (compare_images, compare_image_with_url) by specifying that it works with URLs, not pre-captured images.

  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 implies when to use the tool (comparing two webpages), but does not provide when-not-to-use or highlight alternatives. With sibling tools available, explicit guidance would improve clarity.

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

• compare_image_with_urlA
  4.2/5.0
  Behavior4/5

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

  With no annotations, the description carries the full burden. It discloses that a screenshot is taken, pixel-by-pixel comparison occurs, results include statistics and a diff image, and diff output path behavior (defaults to timestamped file). However, it does not mention network requirements, timeouts, or potential side effects like file creation on disk.

  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?

  Two sentences: first defines the tool's core function, second elaborates on the process. No redundant information, and essential information is front-loaded.

  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 5 parameters, no output schema, and no annotations, the description covers the main purpose and outputs but lacks details on return value format (e.g., difference statistics structure) and potential limitations (e.g., screenshot viewport size). Still largely 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?

  Schema coverage is 100%, so baseline is 3. The description adds value by explaining that the diff_output_path defaults to a timestamped file, and that includeAA controls anti-aliasing inclusion, which is not fully covered by schema descriptions. This extra context justifies a 4.

  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 verb 'compare' and the unique resources: a local image file and a screenshot from a URL. It distinguishes itself from siblings compare_images and compare_urls by specifying this hybrid scenario.

  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?

  While the description implies the tool is best for comparing a local image with a webpage screenshot, it does not explicitly state when to use it over siblings or provide when-not/exclusion criteria.

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