rcsb_get_entry_groups

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

Annotations already establish read-only, idempotent, non-destructive behavior. The description adds meaningful behavioral details: unknown IDs are returned under 'not_found', the fields parameter replaces the curated default selection, and field paths can be discovered programmatically. This goes beyond the annotations without contradicting them.

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 front-loaded with the primary purpose, then uses efficient structured lines for defaults and arguments. Every sentence adds necessary information, with no fluff or repetition of schema fields.

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 tool with a moderate retrieval use case and an output schema present, the description covers the key points: what the tool fetches, default fields, parameter semantics, and edge-case behavior. It does not detail the exact output structure, but the output schema handles that, so the description is sufficiently complete.

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?

The schema provides zero descriptions, so the description carries full burden. It thoroughly explains group_ids with an example and the 'not_found' behavior, and explains fields as an optional GraphQL selection with an example and a discovery method. Both parameters are fully contextualized.

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 opens with a specific verb-resource pairing: 'Fetch entry groups (clusters of related entries) by group ID.' This both defines the resource type and clearly distinguishes it from sibling tools like rcsb_get_entries or rcsb_get_polymer_entity_groups.

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 provides clear context for how to use the tool, including default fields, the use of group_ids with an example, and the behavior for unknown IDs. It also instructs how to discover valid field paths via rcsb_describe_data_object, but it does not explicitly state when to choose this tool over alternative group-related tools.

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