weld

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

No annotations exist, so the description carries the full burden and does so richly: it discloses atomic failure ('changes nothing'), the failure report contents (boundary and non-manifold edges, world box, a safe smaller distance), and the allow_open escape hatch that converts failure into a `warning`. This is exactly the mutation-safety context an agent needs before calling.

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?

Front-loaded with the core action first, then the alternative, then failure semantics — a sensible ordering. It is dense and parenthetically packed ('empty: 0.0001 m, less on objects under 0.3 m'), but every sentence carries distinct information rather than filler.

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 4-param mutation tool with no annotations and no output schema, the description supplies the safety profile, the failure/report contract, and the override flag. An agent has everything needed to call it correctly and predict the result.

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 0%, so the description must compensate, and it does for distance (defaults and size-dependent behavior), where (x, y, z, box), and allow_open (its warning effect). The required `object` parameter and the exact shape of `where` remain undocumented, leaving a small 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?

States a specific verb+resource ('Merge vertices closer than `distance` metres') with concrete defaults and scope, and explicitly distinguishes itself from the sibling repair_mesh. An agent can pick between weld and repair_mesh without opening either schema.

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?

Gives the trigger ('fixes doubled vertices and seams after joining parts'), the exclusion ('for a broken mesh with holes and junk use repair_mesh'), and the correct alternative named explicitly. Nothing is left to inference.

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