fetch_structure

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

With no annotations, the description carries the full burden. It discloses important behavior: fetching the first biological assembly by default and removing unrelated chains. This adds significant value beyond the schema, though it omits potential error conditions or rate limits.

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 concise, with a clear front-loaded purpose, followed by essential behavioral details and parameter explanations. Every sentence contributes meaning without redundancy or fluff.

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 presence of an output schema (not shown), the description does not need to detail return values. It adequately covers the tool's primary behavior and parameters. Minor missing info like error handling or prerequisites prevents a perfect score.

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?

All three parameters are explained with additional meaning beyond the schema: pdb_code is a 4-letter PDB code, obj_name is an optional custom name, and multimer_cutoff is a distance in angstroms with a default of 8.0 suitable for functional assemblies. Since schema coverage is 0%, this fully compensates.

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 fetches a protein structure from the PDB, specifying the resource (PDB) and action (fetch). However, it does not explicitly distinguish from sibling tools like 'load_structure', which might also load structures, so it misses some differentiation.

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 for fetching PDB structures, but provides no explicit guidance on when to use this tool versus alternatives or when not to use it. The default behavior explanation offers some contextual usage hints.

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