bb_draw_textureApply procedural operations to an existing Blockbench texture to add layers of detail without replacing the original pixels. Use it to extend or modify textures already in the project.
Apply a list of ops onto an existing texture (adds to what is already there). Same ops as bb_generate_texture.
| Name | Required | Description | Default |
|---|---|---|---|
| ops | Yes | ||
| seed | No | ||
| target | Yes |
Changes observed during successful MCP inspections.
v2.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries full behavioral burden. It usefully discloses that the operation is additive and mutates existing content, but says nothing about permissions, reversibility (bb_undo exists), rate limits, or whether ops can overwrite prior content. This is thin for a mutation tool.
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 worded sentences with the key scope constraint front-loaded and zero filler. Appropriately sized for the operation.
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 3-param mutation tool with no annotations and no output schema, the description conveys the high-level behavior and a useful cross-reference, but leaves the seed parameter and the op payload structure unexplained. Adequate minimum but with clear gaps an agent would need to resolve.
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 0%, so the description must compensate. It loosely describes 'ops' (a list) and 'target' (an existing texture) but never explains the op object format or the 'seed' parameter at all. The pointer to bb_generate_texture for op format is the only help, leaving two of three params effectively undocumented.
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 (apply ops) and resource (existing texture) and clarifies the additive semantics with '(adds to what is already there)'. It implicitly distinguishes itself from bb_generate_texture, though it does not name that sibling as the 'not this' alternative as explicitly as a 5 would require.
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?
Usage is only implied: the parenthetical 'adds to what is already there' hints this is for modifying rather than creating, pointing the agent toward bb_generate_texture for new textures. There is no explicit when-to-use/when-not statement or named alternative, so the agent must infer the split.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.