get_group_members

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: the exact HTTP call ('POST /v2/getGroupMembers') and request body shape ({accountId, emails:[...]}), so the agent knows precisely what operation occurs. There is no contradiction with the annotations; POST is simply the transport for a read-only resolution.

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?

Three short sentences with no filler: purpose, endpoint/payload, and usage condition each earn their place. The scope-setting clause 'Resolve Google group members for attendee expansion' is front-loaded so the agent grasps the tool's role immediately.

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 two-parameter read-only resolver with the safety profile covered by annotations, the description covers purpose, endpoint, payload, and trigger condition. The notable gap is response format — with no output schema, the agent is not told what a resolved group returns (member email list, member objects, errors), which matters for attendee expansion.

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%, so the description carries the full burden, and it largely delivers: it specifies that emails_json is a 'JSON array' and maps both parameters into the endpoint payload ({accountId, emails:[...]}). The only residual ambiguity is whether emails_json must be a JSON-encoded string (schema type is string) versus a native array, which is not explicitly stated.

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?

Opens with 'Resolve Google group members for attendee expansion,' a specific verb+resource+purpose that immediately distinguishes this from sibling lookups like get_user, get_people, and get_contacts. The closing clause 'Call when an invitee is a group address' further sharpens the boundary by identifying the exact scenario this tool exists for.

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?

'Call when an invitee is a group address' is an explicit trigger condition, giving the agent clear when-to-use guidance. It does not name alternatives or state when not to use this tool, though the attendee-expansion framing implies the contrast with individual person/contact lookup tools.

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