merge_images

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 the merging action and layout options but omits critical details: whether the operation is destructive to input files, authentication requirements, rate limits, error handling, or output specifics (e.g., image quality, format support). For a mutation tool with zero annotation coverage, this is a significant gap.

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

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

The description is a single, efficient sentence that front-loads the core functionality ('Merge multiple images into a single image') and specifies the arrangement methods. There is zero waste, and every word earns its place by clarifying the tool's purpose without redundancy.

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

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

Given the tool's complexity (5 parameters, mutation operation) and lack of annotations or output schema, the description is incomplete. It fails to address behavioral aspects like file handling, error cases, or output format details, leaving gaps that could hinder an AI agent's correct invocation. For a tool with no structured safety or output information, more context is needed.

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

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

Schema description coverage is 100%, so the schema fully documents all 5 parameters. The description adds no additional meaning beyond what the schema provides—it mentions layout options but not details like 'grid' behavior or path requirements. With high schema coverage, the baseline score of 3 is appropriate, as the description does not compensate but also does not detract.

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

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

The description clearly states the tool's purpose: 'Merge multiple images into a single image by arranging them horizontally, vertically, or in a grid.' It specifies the verb ('merge'), resource ('multiple images'), and method ('arranging them'), but does not explicitly differentiate from sibling tools like 'convert_and_resize' or 'resize_image', which focus on transformation rather than composition.

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

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

The description provides no guidance on when to use this tool versus alternatives. It lacks context about prerequisites (e.g., image formats supported), exclusions, or comparisons to sibling tools like 'process_folder' for batch operations. Usage is implied only by the tool's name and description.

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