Build Cuboid Structure

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

Description discloses valuable behavioral traits beyond annotations: builds bottom-up for solid support, caps region at 500 blocks with truncation, skips already-matching blocks, and reports unsupported blocks as failed rather than aborting. This significantly enriches the annotations (readOnlyHint=false, openWorldHint=true, etc.) with operational details.

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 well-structured and front-loaded: the first sentence states the core purpose, followed by a concise args list and clear return/behavior notes. Every sentence adds value, and the length is appropriate for a multi-parameter tool.

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?

Despite no output schema, the description fully documents the return shape ({ placed, skipped, failed, message }) and key behaviors (truncation, skip, failure handling). It covers use cases, build order, and limitations, making it complete for an agent to invoke correctly without further guesses.

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 low (13%), with only block_name described. The description adds meaning for 'hollow' (outer shell vs solid) and clarifies that coordinates are 'two corner coordinates', but does not explain each coordinate pair's semantics or the relationship between x1/y1/z1 and x2/y2/z2. It partially compensates for the schema gap but is not comprehensive.

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 the tool 'Fills a cuboid region between two corner coordinates with a block from inventory', specifying the verb, resource, and intent. It differentiates from siblings like place_block (single block) and clear_area (removal) by describing bulk filling for walls, floors, platforms, and boxes.

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?

Provides clear context for when to use the tool ('for walls, floors, platforms, boxes') and implies bulk building vs single placement. Does not explicitly mention alternatives or exclusions, but the use cases are sufficiently clear for an agent to select it appropriately.

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