draw_brush

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

Annotations declare readOnlyHint=false and openWorldHint=false, so the agent already knows this mutates local state. The description adds meaningful input semantics (brush character encoding, anchor placement) but never says which file/layer/frame is affected, that it is destructive to existing pixels, or that 'filename' is required – gaps the annotations alone do not close.

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 compact Args block; every line earns its place and there is no filler. The only minor cost is the verbose brush example, which is nonetheless useful.

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 output schema and low schema coverage, the description covers the novel brush/point semantics but omits required-parameter guidance (filename) and the frame/layer targeting behavior, leaving an agent to infer how the stamp is scoped.

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 only 29%, so the description carries real weight, and it does document brush, points, color, and anchor well (including the character-fill rule and the center/topleft values). However, three parameters – filename, frame, and layer – are undocumented in both schema and description, leaving the coverage gap only partly filled.

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 opening line gives a specific verb (stamp) and resource (custom brush shape) plus the target (a list of points), which is clear enough to distinguish it from pixel- or line-drawing siblings. It does not explicitly contrast itself with the closest alternatives like stamp_pattern or draw_pixel_map, so it stops short of a 5.

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 reach for this tool versus stamp_pattern, draw_pixel_map, or draw_pixels, nor any prerequisites (e.g. an open sprite, valid layer/frame). The Args block documents inputs but never states the usage context or exclusions.

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