add_text

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

With no annotations, the description carries the full burden. It does disclose the return shape ({layer_name, layer_id, text_width, text_height, position}), which is genuinely useful since there is no output schema. But it says nothing about mutation side effects: whether the new layer becomes active, whether it is undoable, or what happens if image_index is out of range.

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?

Front-loaded one-line purpose followed by a clean parameter list and a return line. The parameter restatement is somewhat duplicative of the schema but is justified given 0% schema coverage. No filler or marketing language.

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 medium-complexity creation tool with no annotations and no output schema, the description covers purpose, all parameters, defaults, and return values. The main gap is the absence of any behavioral context about the mutation (target image resolution, layer stacking, undo), which an agent modifying a document would want.

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 0%, so the description must compensate, and it does. Every one of the seven parameters is explained with meaning beyond the schema: coordinate origin for x/y, accepted font families, pixel units for size, and accepted color formats (CSS name, hex, rgb()). Defaults are restated consistently with the schema.

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 opens with a specific verb and resource: 'Add a text layer to an image.' That is unambiguous and distinguishable from most siblings. It does not, however, differentiate itself from close alternatives such as edit_text or create_layer, which the agent would need to choose between.

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?

There is no guidance on when to use this versus edit_text (modifying existing text) or create_layer. The reader must infer that this tool is for new text and edit_text is for existing text. No prerequisites (e.g. an open image) or exclusions are stated.

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