molecule_info

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

Annotations already declare the tool as read-only, idempotent, and non-destructive. The description adds value by specifying exactly what the tool computes (atom counts, frame count, chains, residues) and that it can load an optional trajectory, which goes beyond the annotation metadata.

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 two short sentences, immediately stating the main action and listing the computed outputs. No redundant words, and the structure is front-loaded with the tool's primary purpose.

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?

Despite lacking an output schema, the description adequately explains the return value (summary counts). The tool is simple and the description covers all key aspects: input, optional parameter, and output content.

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%, and the description only restates parameter names ('structure', 'trajectory') without clarifying their format (e.g., file path or identifier) or constraints. The optionality of trajectory is already captured by the schema default of null.

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 loads a structure and trajectory and reports a summary with specific counts (atoms, frames, protein/water/backbone, chains, residues). This specific verb+resource combination distinguishes it from siblings like count_atoms or rmsd that focus on single metrics.

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 usage when a broad structural summary is needed (e.g., assessing system composition) but does not explicitly state when to avoid using it or provide alternative tools for specific queries.

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