Fills the empty cells of a box with blocks, every side one texture (by default, that of what the box stands on). Cells in restricted zones, and where someone stands, are skipped.
| Name | Required | Description | Default |
|---|---|---|---|
| rows | Yes | [from, to], or [one] | |
| layers | Yes | [from, to], or [one] | |
| columns | Yes | [from, to], or [one] | |
| texture | No | A name or number from textures |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations declare a non-read-only but non-destructive write, and the description is consistent with that by scoping the write to empty cells only. It adds real behavioral context the annotations cannot convey: the default texture is inherited from the block the box stands on, and restricted zones plus cells occupied by agents are silently skipped rather than erroring.
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 tightly packed sentences with no filler. The core action comes first, and the qualifying behavior (skipped cells, texture default) follows immediately where an agent needs it.
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 parameterized write with no output schema, the description covers the action, the default-value behavior, and the two silent-skip conditions, which is most of what an agent needs before calling. Minor gaps remain around coordinate orientation and behavior when no empty cells exist.
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% (baseline 3), and the description adds meaning the schema lacks by explaining the `texture` parameter's default inheritance behavior. It still says nothing about how rows/columns/layers index the world, but the schema already defines those as [from,to]/[one] ranges.
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 concrete verb and resource: it fills empty cells of a box with blocks, and it names the affected unit (cells, with one texture per side). This is clearly distinguishable from siblings like remove_blocks, paint_faces and add_object, though it never names those alternatives explicitly.
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 when-to-use guidance, no mention of prerequisites (e.g. needing a texture name from `textures`, or a zone already defined), and no routing to alternatives such as paint_faces or add_object. The only usage signal is implicit: it operates only on empty cells.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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