Compare replacement direction previews

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

There are no annotations, so the description must carry the behavioral burden. It discloses the high-level behavior ('Build one visual board... reject candidates') and some evaluation criteria, but it does not explain whether the board is persisted, what output is returned, whether it modifies any inputs, or what happens when output_path is omitted. This leaves key behavioral aspects under-specified.

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?

Two sentences, front-loaded with the main action and followed by a concise workflow note. Every phrase contributes to understanding when and why the tool should be used, with no filler or repetition of schema details.

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?

Given the nested schema, four parameters, no parameter descriptions, and no output schema, this description is too sparse for a fully informed invocation. It gives a useful workflow position but omits important context about the rejected baseline, output_path behavior, and return value, leaving an agent to guess at semantics not recoverable from the schema.

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. It adds meaning by mapping 'two to four' to the candidates array, and 'image-making method, composition, and enough core visual axes' to the axis fields and minimum_changed_axes concept. However, it does not explain the required 'rejected' object or the optional 'output_path' parameter, so compensation is partial.

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 clearly states a specific action: build a visual board for two to four opening-frame previews and reject candidates that fail material-change criteria. It is not a tautology and identifies the resource ('replacement direction previews') and the workflow position, though it does not explicitly name sibling tools to distinguish itself.

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?

It provides clear usage context with 'Use before expanding any replacement into a full set,' which tells an agent when in the workflow to invoke this tool. It does not, however, state when not to use it or mention alternative sibling tools explicitly.

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