Convert a local image

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

Annotations establish it is a non-read-only, non-destructive, non-idempotent, closed-world write. The description adds genuinely non-obvious traits: JPEG transparency is filled with the requested background, the output format and dimensions are verified after writing, and metadata may be stripped by re-encoding — a real data-loss caveat that the destructiveHint=false annotation does not convey.

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?

Three tight sentences, zero filler. The capability and format matrix come first, then the notable behaviors, then the caveat — appropriately front-loaded and each sentence carries distinct information.

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?

With no output schema, the description usefully states what the tool does with the output ('writes a new local image and verifies its format and dimensions'). Remaining gaps are modest: no mention of overwrite behavior on an existing output_path, and no return-value shape, but the critical call requirements are covered.

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 coverage is 40%, so two of the non-path parameters (format, quality) lack schema descriptions. The description recovers the format enum implicitly and explains the background parameter's role in JPEG transparency, but quality (default 0.92) and its interaction with lossless PNG/WebP are never addressed. Partial compensation only.

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?

States a specific verb and resource ('Convert a still JPEG, PNG, or WebP into JPEG, PNG, or WebP') plus the output artifact ('Writes a new local image'). This is clearly distinct from sibling operations like abox_image_compress, abox_image_resize, or abox_svg_to_image, though it never explicitly names them for contrast.

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?

Usage is implied by the format-pair framing, so an agent can infer this is for format change rather than size or dimension change. However, there is no explicit 'use X when Y' routing against the large family of image siblings, and no stated preconditions beyond the local-path requirement carried by the schema.

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