Server Quality Checklist

Tool Scores

• list_modelsA
  4.3/5.0
  Behavior3/5

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

  No annotations are provided, so the description must disclose behavioral traits. It states the tool lists information but does not mention whether it is read-only, cached, or subject to any limitations. The output schema fills some gaps, but additional details on side effects or constraints would be beneficial.

  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 a single, well-structured sentence that immediately conveys the tool's purpose. No unnecessary words; every part is relevant.

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

  Completeness5/5

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

  Given zero parameters and the existence of an output schema, the description fully covers the tool's purpose and output. The context of sibling tools further clarifies its role. No additional details are needed.

  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 input schema has zero parameters, so schema coverage is 100%. The description adds value by specifying what the output contains (friendly aliases, real IDs, usage notes), which is more than the empty schema provides. Baseline is 4 due to full 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 uses the verb 'List' and specifies the exact resource: friendly model aliases, their real Vertex IDs, and usage notes. This distinguishes it from sibling tools that edit or generate images.

  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?

  Although no explicit when/when-not guidance is given, the context of sibling tools (edit_image, generate_image) makes it clear that this tool is for listing model information. A brief note on when to use it instead of other tools would improve clarity.

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

• generate_imageA
  4.5/5.0
  Behavior4/5

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

  No annotations provided, so the description carries full burden. It discloses key behaviors: loop behavior for multiple images, per-model limits (imagen-4-ultra supports 1), file saving to output_dir with fallback defaults, and preview return via return_image. It could mention side effects of file writes explicitly, but overall it is transparent.

  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 structured with a one-line summary, detailed Args section, and Returns. It is longer but each sentence is informative. No redundancy; it could be slightly more concise in the Returns description, but overall well-organized.

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

  Completeness5/5

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

  With 6 parameters (1 required), no output schema, and no annotations, the description covers all input details, explains default behavior, and describes the return value (list of paths and optional image). It mentions limitations like model-specific constraints. It is complete for an agent to invoke correctly.

  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?

  Schema coverage is 0%, so description must explain parameters. It does so thoroughly: prompt (text description), model (friendly aliases with examples), aspect_ratio (with examples and note on model-dependence), n (number with loop behavior), output_dir (default path logic), return_image (preview). This adds significant meaning beyond 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 starts with 'Generate image(s) from a text prompt,' which is a clear, specific verb and resource. The sibling tools 'edit_image' and 'list_models' are distinct, so no confusion.

  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?

  While the description does not explicitly state when to use this tool versus siblings, the focus on generation from text prompts implicitly distinguishes it from editing or model listing. A more explicit usage guideline would be better but is not necessary given clear sibling names.

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

• edit_imageA
  4.6/5.0
  Behavior4/5

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

  With no annotations, description carries full burden. It discloses that the tool saves the result to a file, returns a path and optional preview. Describes default model and output directory fallback. Missing details about potential side effects or permission requirements, but transparent enough.

  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?

  Well-structured with bullet points for args. Front-loaded with core purpose and key differentiators. No unnecessary words. Efficient and readable.

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

  Completeness5/5

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

  For a tool with 5 parameters and no output schema, the description covers inputs, behavior, return format (path + optional image), and default behaviors. Complete for an agent to invoke correctly.

  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?

  Schema coverage is 0%, so description must compensate fully. It explains each parameter: image_paths (absolute paths), prompt (instruction), model (two named options), output_dir (defaults), return_image (boolean, preview). Adds meaning beyond 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?

  Description clearly states 'Edit or fuse input image(s) with an instruction' and distinguishes between one image (edit) and two or more (fusion). It also warns that Imagen models are rejected, differentiating from sibling tool generate_image. Purpose is specific and unambiguous.

  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?

  Provides explicit usage guidance: one image = edit, two or more = fusion. Warns against using Imagen models. Lists parameters with defaults and behavior. Could be more explicit about when not to use (e.g., text-to-image use cases), but adequate.

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