Edit a mesh

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

With no annotations, the description carries full behavioral burden. It usefully discloses in-place mutation, the append-vs-overwrite distinction of merge, and key-based deletion. However, it does not say whether redefining geometry discards existing faces not listed, whether faces indices/UVs are preserved, or whether the operation is reversible (bb_undo exists but is not referenced).

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?

Four dense sentences, front-loaded with the core action and mode semantics, with no filler. The key-discovery pointer is efficiently packed into the final sentence.

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 6-parameter mutation tool with no annotations and no output schema, the description covers the mode logic and key lookup well, but leaves 'target' unspecified and omits failure/destructive semantics. Adequate but leaving meaningful inference to the agent.

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?

Despite only 33% schema description coverage, the description supplies meaning for nearly every parameter: vertices, faces, merge, delete_faces, and delete_vertices are all explained in prose. The required 'target' parameter is left unexplained, which is the one clear 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 opens with a specific verb+resource: 'Modify an existing mesh in place', which clearly distinguishes editing from siblings like bb_add_mesh or bb_add_cube. It stops short of explicitly naming the alternative tools, but the purpose is unambiguous.

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?

It states the two operating modes clearly: vertices+faces redefine geometry, while merge:true appends, and delete_faces/delete_vertices remove by key. It also routes the agent to bb_list_elements {include_geometry:true} to discover keys. No explicit when-not-to-use or sibling comparison, but the mode selection guidance is solid.

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