Get a contact group

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

Beyond the readOnly/idempotent annotations, it discloses the conditional behavior of max_members, the format of memberResourceNames as people/<id> resource names, and the significance of the etag for safe renames. This is useful operational detail that annotations alone do not convey.

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?

Two well-structured sentences pack in return fields, member behavior, cross-tool routing, and etag semantics without redundancy. The most important action and resource appear first, and every phrase earns its place.

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 rich annotations and fully described schema, the description adds the missing behavioral and workflow context: what members look like, how to get their details, and how the etag is used downstream. No critical gap remains for an agent to select and invoke the tool correctly.

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%, so the baseline is 3, but the description adds meaning by explaining that max_members controls whether members are included and by sourcing resource_name from list_contact_groups. It also ties the etag to update_contact_group, which is not evident from the schema alone.

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?

Description opens with a specific verb and resource: "Fetches one contact group by resource name," then concretely enumerates the fields returned. It also distinguishes itself from sibling tools by calling out that this is the only way to get group members and that the etag feeds update_contact_group.

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 gives clear context: use this tool to fetch a single group and especially to obtain member resource names, since that is the only way the API returns them. It points to batch_get_contacts and update_contact_group as follow-up tools, though it does not explicitly state when to prefer list_contact_groups over this tool.

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