compose_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 states the tool composes a new image but doesn't cover critical aspects like whether this is a read-only or destructive operation, authentication needs, rate limits, or what the output looks like (e.g., format, size). For a tool with no annotations and an implied mutation (creating a new image), this is a significant gap in transparency.

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 purpose without unnecessary words. Every part ('Compose a new image,' 'using multiple input images,' 'and a guiding prompt') contributes directly to understanding the tool's function, making it appropriately concise and well-structured.

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 complexity of an image composition tool with no annotations, no output schema, and incomplete parameter documentation (67% coverage), the description is inadequate. It doesn't address behavioral traits, output details, or usage guidelines, leaving significant gaps for the agent to infer how and when to use this tool effectively.

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 67% (2 out of 3 parameters have descriptions). The description adds minimal value beyond the schema: it mentions 'multiple input images' (implied by the 'images' array with minItems:2) and 'guiding prompt' (matching the 'prompt' parameter). It doesn't explain the 'saveToFilePath' parameter or provide additional context like image format constraints. With moderate schema coverage, the baseline of 3 is appropriate as the description doesn't significantly compensate for gaps.

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: 'Compose a new image using multiple input images and a guiding prompt.' It specifies the verb ('compose'), resource ('new image'), and key inputs (multiple images + prompt). However, it doesn't explicitly differentiate from siblings like 'edit_image' or 'generate_image' beyond mentioning 'multiple input images,' which might be insufficient for clear sibling distinction.

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 doesn't mention sibling tools like 'edit_image' or 'generate_image,' nor does it specify prerequisites such as needing at least two images. Without any when-to-use or when-not-to-use context, the agent lacks direction for tool selection.

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