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

Beyond the readOnlyHint=true annotation, the description discloses that the tool performs no world read, reservation, or mutation, and that it returns a deduplicated protected batch body. This gives the agent a clear side-effect profile and return nature without contradicting the annotation.

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 two sentences with no filler. The action and resources are front-loaded, followed by side-effect and workflow guidance. Every sentence adds value.

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 generator with no output schema, the description covers the essential behavior, side effects, and next step. The phrase 'protected batch body' is somewhat vague, but combined with the readOnlyHint and the 'Preview then explicitly build' instruction, the agent has enough to call the tool correctly.

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 only 14%, so the description must compensate. It adds meaningful semantics for coordinates ('minimum corner') and rotation, but it does not explain the type/builder parameters or the exact meaning of the returned batch body. The enum values in the schema help, but the description only partially fills the coverage gap.

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 uses a specific verb ('Generate') and names the exact resources produced: pillar, arch, staircase, room-5x5, letter-w. It also clarifies the key positioning concept ('minimum corner'), making the tool's role distinct from world-mutating siblings like build or place_cube.

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 description clearly indicates this is a planning-only tool by stating 'no world read, reservation or mutation' and instructs the agent to 'Preview then explicitly build.' It implies the workflow but does not explicitly name preview_build or build as the next-step alternatives.

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