create_group_direct_message

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

Description claims idempotency ('Idempotent by exact sorted member set') but annotation idempotentHint=false indicates the tool is not guaranteed idempotent. This is a direct contradiction. Additionally, no other behavioral traits (like permissions or error conditions) are disclosed beyond what annotations provide.

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?

Four sentences, no wasted words. Front-loaded with purpose, then parameter details, then idempotency, then alternative. Every sentence adds value.

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?

Covers purpose, usage, idempotency, and parameter format. Mentions return value indicator ('created: false'). Lacks error handling details (e.g., if a person not found), but with a single parameter and output schema, this is nearly 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?

Schema coverage is 100% and the description largely echoes the schema's explanation for the 'people' parameter. The description adds minimal new meaning (e.g., 'authenticated account is included automatically' is also in schema description). Baseline 3 applies.

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 uses specific verb 'Open a group direct-message conversation' and clearly identifies the resource (group DM) and scope (at least two other members). It distinguishes from sibling tool create_direct_message by specifying the alternative for one person.

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?

Explicitly states when to use (for group DMs with 2+ others) and when to use an alternative (one other person → create_direct_message). Also mentions idempotency and automatic inclusion of authenticated user, providing clear context.

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