PostSession

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

No annotations are provided, so the description carries the full burden. It discloses that this is a write operation ('Set'), requires authentication (JWT token), and has a prerequisite (previous authentication via a specific API route). However, it lacks details on behavioral traits like error handling, response format, or side effects (e.g., how the session ID affects subsequent requests).

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 sentences, front-loaded with the core purpose and followed by essential usage guidance. Every sentence adds value: the first defines the tool's action, and the second specifies prerequisites. There is no wasted text or unnecessary elaboration.

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 no annotations, no output schema, and 0 parameters, the description is moderately complete. It covers purpose and prerequisites but lacks details on behavioral aspects (e.g., what happens after setting the session, error scenarios) and output. For a tool with no structured data, more context on behavior would improve completeness.

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 input schema has 0 parameters with 100% coverage, so no parameters need documentation. The description appropriately does not discuss parameters, focusing instead on usage prerequisites. A baseline of 4 is applied since no parameters are present, and the description adds context without redundancy.

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 the specific action ('Set the cookie session ID of a customer') and identifies the resource ('customer'), distinguishing it from sibling tools that primarily retrieve data (e.g., GetCartsId, GetProducts) or handle other operations like authentication or payments. It avoids tautology by explaining the tool's function beyond its name.

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 explicitly states when to use this tool ('The customer must be previously authenticated with the `/auth/customer/{provider}` API route first') and provides a prerequisite (JWT token required in the header). It distinguishes usage from sibling tools by focusing on session management rather than data retrieval or other operations listed in the sibling tool names.

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