create_private_chat

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

Without annotations, the description discloses the operation (create) and return value (new chat ID). However, it does not mention potential side effects or required permissions.

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 extremely concise: two sentences plus structured Args/Returns. It is front-loaded with the purpose and contains no extraneous information.

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 simple create tool with one parameter and an output schema, the description provides sufficient context: what it creates, the parameter meaning, and the return value. Minor omission of error conditions.

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 description explains that user_id is the 'Numeric ID of the user to start a PM with', adding meaningful semantics beyond the schema's type-only definition, which had 0% coverage.

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 it creates a personal (PM) chat with another user, using specific verb and resource. It distinguishes from sibling tools like create_group_chat and create_thread_chat.

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 for one-on-one direct messaging via the term 'personal (PM) chat', but does not explicitly state when to use or avoid this tool compared to alternatives.

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