image_add

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

No annotations are supplied, so the description carries the full behavioral burden. It usefully discloses that src can be a local file path, a remote URL, or Base64, and that isBackground produces a full-bleed background rather than just a back-positioned layer. However, it says nothing about remote fetch behavior, local-file access constraints, or what happens on load failure.

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 sentences, no filler, with the core action stated first and the source-form detail immediately after. The second sentence is long but each clause adds usable information; nothing is redundant.

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?

For a 7-parameter mutation tool with no annotations and no output schema, the description covers src and isBackground well and defers the geometry parameters to the schema. It does not indicate what the call returns (e.g., a layer id) or any error/permission behavior, leaving a meaningful gap for an insert operation.

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 already documents all seven parameters; the baseline is 3. The description adds examples of accepted src formats and clarifies that isBackground yields a full-bleed background (vs. the schema's terse "sends layer to back"), which is modest extra value but not required for invocation.

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 ("Adds an image layer to the canvas") that an agent can immediately separate from siblings like svg_add, sticker_add, shape_add, and text_add. The scope is unambiguous and front-loaded.

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?

Gives clear usage context: it enumerates the three acceptable source forms (local path, public URL, Base64 data URL) with examples, and explains the isBackground shortcut. It never explicitly names when to prefer it over siblings such as assets_load_from_path or image_crop, so it stops short of full routing guidance.

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