merge_vertices

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

No annotations are provided, so the description carries the full burden. It discloses the return value (confirmation dict with removed count) and the threshold range, but does not mention that the operation is destructive or modify the mesh permanently. Some behavioral context is missing.

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 very concise, with a one-line summary followed by structured Args and Returns sections. No unnecessary words, and it effectively communicates the essential information in a compact format.

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?

Given the simplicity of the tool (2 parameters, no enums, output schema exists), the description is mostly complete. It covers purpose, parameters, and return value. However, it does not mention whether the operation works on all vertices or only selected ones, or if it can be undone.

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 adds significant value. It explains object_name as 'Name of the mesh object' and threshold as 'Maximum distance between vertices to merge. Range: 0.0-10.0.' This clarifies what each parameter means beyond the schema's type and title.

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 'Merge vertices by distance,' specifying the action (merge) and resource (vertices) with a criterion (distance). This is distinct from sibling tools like dissolve_verts, which remove vertices without merging.

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?

The description implies when to use this tool (for merging nearby vertices) but does not explicitly state when not to use it or mention alternatives like dissolve_verts or boolean_operation. No usage context is provided beyond the basic operation.

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