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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does an excellent job by flagging the token as a sensitive, high-privilege secret and warning against logging or exposing it. It also discloses the token cost and the prerequisite call to get_connected_accounts. It doesn't mention rate limits or error behavior, but those are less critical given the security warnings and output schema.

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 concise and well-structured: a clear purpose statement, a bold security warning, a brief usage instruction, and a cost note. Every sentence serves a distinct purpose with no redundancy. The most important information (what the tool does) is front-loaded.

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 the tool's sensitivity and complexity (5 parameters, security implications), the description is remarkably complete. It covers purpose, prerequisite, security handling, cost, and connection selection. The output schema exists to explain return values, and the schema covers all parameters, so the description fills the remaining gaps effectively.

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 100% description coverage, with each parameter already explained in detail (e.g., user_id, actor_sub, clerk_instance_id). The description adds marginal value beyond the schema, such as reinforcing the use of clerk_instance_id for targeting a specific connection. Since the schema does the heavy lifting, a baseline score of 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 clearly states the tool's specific function: creating an actor token for impersonation. The verb 'Create' plus the resource 'actor token' and the purpose 'lets one user impersonate another' make it unambiguous. It also distinguishes this from sibling token tools like create_m2m_token or create_session_token by emphasizing impersonation.

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 provides a clear usage context: it instructs the agent to call clerk.get_connected_accounts first and explains how to choose the connection via clerk_instance_id. While it does not explicitly name alternative tools to avoid, the prerequisite and connection targeting give solid practical guidance. Missing explicit 'when not to use' but enough context for correct invocation.

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