export_selection_mask

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

No annotations are supplied, so the description carries the full disclosure burden. It does reveal the output format and the white=selected polarity, which is genuinely useful, but says nothing about what happens with an empty/absent selection, whether the target file is overwritten, or what the call returns — all material for a write-to-disk tool.

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?

A single front-loaded sentence that identifies the saved artifact and its pixel convention with no filler. It is appropriately sized, though the brevity comes partly at the cost of the missing parameter and behavior detail noted above.

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 two-parameter side-effect tool with no annotations and no output schema, the description covers the core purpose and output encoding but leaves the path contract, the invert flag, and failure/overwrite behavior undocumented — enough to attempt a call, not enough to call it confidently.

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% across two parameters, so the description must compensate and largely does not: 'path' is never identified as an output file path (versus a directory, with or without extension), and 'invert' is never explained, only indirectly hinted at by the 'white = selected' convention.

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 ('Save the current selection as a greyscale PNG mask') plus the encoding convention (white = selected), which clearly separates it from the generic export_image sibling. It stops short of naming export_image or set_selection explicitly, so the differentiation is implied rather than stated.

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 trailing phrase 'for inpainting models' implies the intended downstream use, but there is no explicit statement of when to pick this over export_image or whether a selection must first be created via set_selection. Usage is inferable but not spelled out.

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