create_group

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

The annotations already mark the operation as non-read-only and non-idempotent, so the description does not need to restate that. It adds valuable behavioral detail beyond the annotations: failed member additions do not roll back the entire group, and the error reports which members failed so they can be retried via `manage_group_members`. This is a non-obvious partial-failure behavior that an agent should know before calling.

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 two short paragraphs with no filler. The core action is front-loaded in the first sentence, and the important failure caveat is separated into the second paragraph. Every sentence adds meaningful guidance.

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 two parameters, the rich input schema, and the presence of an output schema, the description is mostly complete. It covers the main purpose, optional membership, and the partial-failure behavior. A minor gap is not explicitly stating that adding members to an existing group should use `manage_group_members`, though the 'initial members' wording and retry reference imply as much.

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 tool-level description adds little parameter detail beyond calling members 'initial members' and alluding to malformed invites. However, the input schema compensates with structured descriptions for `GroupMemberInput`, `user_id`, `email`, `first_name`, and `last_name`, so an agent reviewing the schema can understand the member modes. The description does not shoulder the full burden, but the schema largely fills the gap.

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 states a specific verb and resource: 'Create a new Splitwise group and optionally add its initial members.' It also names a related sibling tool, `manage_group_members`, for handling failed member retries, which sharpens the boundary between creating a group and later managing its members.

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 clearly establishes when to use the tool: when creating a new group, with optional initial member adds. It also explicitly points to `manage_group_members` as the retry path for members that failed during creation, giving a concrete alternative for that scenario. It does not discuss broader exclusions, but the context is clear enough.

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