Trace walls from a scan

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

Annotations already establish that the tool is not read-only and not destructive, and the description adds meaningful behavioral context: walls are 'create[d] in one undo step' and tracing is based on the background image. This goes beyond the structured annotations and helps the agent anticipate undo granularity and side effects.

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?

The description is compact: two sentences, with the core purpose front-loaded and no filler. The verification tip is terse, but every clause contributes either purpose, behavior, or workflow context.

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 7-parameter schema is fully documented, annotations cover safety traits, and an output schema exists, the description supplies the essential behavioral frame: trace from background, create in one undo step, and verify with render_plan. It could clarify what trace_background is and whether trace_walls depends on an existing background, but it is not critically incomplete.

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 100%, so every parameter already has a type, default, and explanation. The description mentions h (wall height) and its default, but it only repeats information already present in the schema rather than adding new semantic detail. This matches the baseline of 3 for fully documented schemas.

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 names the specific action ('Trace walls'), the resource ('the background image'), and the output ('create them'), which is clear enough for an agent to understand what the tool does. It references trace_background for analogy, but the boundary between trace_walls and trace_background is not fully explicit, so it falls 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 explicit guidance on when to use trace_walls versus alternatives, despite trace_background being a very similar sibling. The only practical hint, 'Check with render_plan bg=0.5', tells the agent how to verify afterward but does not explain selection conditions or exclusion criteria.

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