rms_cur

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

With no annotations provided, the description carries the full burden. It discloses the critical behavioral trait that it does not move anything, implying a non-destructive operation. It also explicitly mentions the constraints (matching atom counts) and differentiates from mutation-like tools (align/super), making side effects and scope clear.

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 well-structured and efficient, starting with the core action and immediately clarifying the non-mutating nature. It then provides usage context and compares with siblings in a compact way. Every sentence adds value, with no redundancy.

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 tool's simplicity, the output schema, and the rich sibling context, the description is complete: it covers purpose, usage conditions, exclusions, and the critical atom-count prerequisite. It fully explains what the tool does without needing to describe return values since an output schema exists.

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 100% with descriptions for both parameters ('First selection', 'Second selection, same number of atoms'). The main description adds the context that both selections must have matching atom counts, which slightly supplements the schema, but it does not explain selection syntax or ordering details. This is baseline for high schema coverage.

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 the tool measures RMSD between two selections without moving anything, which is a specific verb+resource. It distinguishes itself from sibling tools align, super, and superposition_view by emphasizing it does not alter the structure and only reports the current distance.

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?

Explicit usage guidance is provided: use when structures are already superposed or to know the current positional difference. It names alternatives (align, super for minimization, superposition_view for visual analysis) and states the requirement of matching atom counts, giving clear when-to-use and when-not-to-use context.

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