create_session

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

With no annotations provided, the description carries the full behavioral burden. It discloses the operation ('create') and the immediate return behavior (session name and STARTING status), but it does not mention potential side effects, duplicate name handling, error conditions, or whether the session persists. This is adequate but not rich.

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?

Two short sentences with no filler. The core action is stated first, followed by the return value and the logical next step. Every sentence earns its place.

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 creation tool with one optional parameter and no output schema, the description gives enough: what it does, what it returns, and the next tool to call. It could mention failure modes or prerequisites, but the essential context for correct invocation is present.

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%, so the schema already documents the single optional 'name' parameter as auto-generated if omitted. The description adds the output relevance of the session name but does not go beyond the schema's parameter documentation. Baseline 3 is appropriate.

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 a specific verb and resource: 'Create a new WhatsApp session.' It clearly distinguishes itself from sibling tools like list_sessions and get_session_status by stating its unique action, and it adds the return value context (session name and STARTING status).

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 positions this tool as the entry point: create a session, then pair it with get_qr_code next. It does not explicitly state when not to use it or mention alternatives like request_pairing_code, but the sequential guidance is enough to convey the intended usage context.

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