create_p2p_chat

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

With no annotations, the description carries the full burden. It discloses the idempotent behavior ('Create or get') and the return type ('numeric chat_id'), which adds useful context. However, it does not mention potential side effects, permissions, or error conditions (e.g., invalid user_id). This is a minimal but adequate disclosure for a simple tool.

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 a single sentence with 17 words, front-loaded with the core action and result. There is no redundant information or filler. The '[User Identity]' prefix is a minor label but does not detract from conciseness.

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 tool with one parameter and no output schema, the description is reasonably complete: it states the action (create/get), the resource (P2P chat), and the return value. It does not explain error handling or what to do with the chat_id, but these are less critical given the simplicity. The schema and sibling tools provide enough surrounding context for correct invocation.

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 100% (user_id has a description), so the baseline is 3. The description does not add any parameter-specific meaning beyond what the schema already provides. It correctly implies the parameter identifies the target user, but the schema already states 'Target user ID from search_contacts'.

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 'Create or get a P2P (direct message) chat' with a specific verb and resource, and it explicitly mentions the return value ('Returns numeric chat_id'). This distinguishes it from sibling tools like create_group (group chat) and send_to_user (sending messages), making its purpose unambiguous.

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 direct messaging by saying 'P2P (direct message) chat', but it does not explicitly state when to use this tool vs alternatives like create_group or send_to_user. There is no mention of prerequisites (e.g., needing to search contacts first) or exclusions, so the guidance is only implied, not explicit.

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