session_login_as

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

Since no annotations are provided, the description carries the behavioral burden. It explicitly discloses that this tool mutates the long-lived session and requires confirm, which are the key side-effect and safety traits. It doesn't elaborate on reversibility or permissions, but the core mutation behavior is clearly stated.

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 compact and front-loaded: purpose first, then usage guidance, then parameter notes. Every sentence earns its place with no filler.

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 two-parameter session tool with an output schema, the description covers what the tool does, when to prefer an alternative, and the key side effect. It could mention how to revert the session change, but the essential information for selecting and invoking the tool 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?

The description adds meaning for username ('Account to impersonate') and says confirm is required, which helps given the 0% schema description coverage. However, 'confirm: Required' is ambiguous: it doesn't explicitly say confirm must be set to true, and it seems to conflict with the schema's required list which only includes username.

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 states a specific verb and resource: 'Switch the session into another account (login-as).' This clearly identifies what the tool does and distinguishes it from per-call impersonation via the impersonate= argument.

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 advises preferring the impersonate= argument on individual tools because it does not mutate the long-lived session. This is an explicit when-not-to-use and alternative, making the appropriate usage clear.

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