Design Creation

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

Annotations already declare readOnlyHint=false, openWorldHint=true and non-idempotent, so the safety profile is covered. The description adds real value beyond that: results are written to disk and their paths returned, which tells the agent this is a side-effecting, file-producing operation. It does not mention credit consumption or rate limits, but with annotations present this is adequate.

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, front-loaded with the core action, then the variant list, then usage and output behavior. The variant enumeration partially duplicates the schema, but the structure is efficient and nothing is buried.

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?

With 20 parameters, no output schema and a write operation, the description covers the essentials by naming the return shape (saved file paths) and the variant modes. Missing only cost/credit awareness and disambiguation from td_design_generation, both of which an agent would want before invoking.

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 all 20 parameters are already documented — including the per-variant output counts that the description repeats ('prime 1-5, new 1-5, old 1-4'). The description adds nearly nothing beyond what the schema states, so the baseline 3 applies.

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 — 'generate design variations from the source image' — and enumerates the variant modes. However, it never distinguishes itself from the near-identically named sibling td_design_generation, so an agent cannot tell from the text alone which of the two generation tools to pick.

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?

'Best for: generating fresh design variations from a reference image without writing prompts' plus concrete scenarios (filling collection gaps, style-consistent range, quick concept exploration) gives clear when-to-use context. There is no when-not-to-use guidance or explicit pointer to td_design_generation / td_sketch_to_design, which is the missing half.

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