rcsb_get_polymer_entity_groups

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is known. The description adds meaningful behavior: default fields returned, unknown IDs handled via 'not_found', and fields override capability. This goes beyond annotation information without contradicting it.

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 compact and well-structured with a clear purpose sentence, default fields note, and an Args section. Every sentence serves a purpose, and the format is easy to scan without unnecessary verbosity.

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 read-only data-fetching tool with an output schema and strong annotations, the description covers the essential aspects: what it retrieves, defaults, parameter semantics, and unknown-ID handling. It omits potential details like pagination or rate limits, but these are less critical given the straightforward getter nature and existing schema.

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 0%, but the description fully compensates by explaining both parameters: group_ids as sequence-cluster group IDs with example and unknown-ID behavior, and fields as an optional GraphQL selection with a discovery path. This provides substantial meaning beyond the bare schema.

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 polymer entity groups, provides a concrete example (sequence clusters with "85_70"), and distinguishes itself from sibling group-fetching tools like rcsb_get_nonpolymer_entity_groups and rcsb_get_entry_groups. The verb 'fetch' and specific resource 'polymer entity groups' are unambiguous.

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 by naming the resource and providing example IDs, but does not explicitly state when to use this tool over alternatives (e.g., rcsb_get_entry_groups) or give exclusions. It does point to rcsb_describe_data_object for field discovery, which is helpful but not a full usage guideline.

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