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

The description discloses behavioral details beyond the annotations: it states the switch itself requires nothing and causes no errors, but downstream tools will return 401 until login succeeds. This gives agents accurate expectations about side effects and dependencies. It does not contradict any annotation and adds useful context about the required token.

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 three concise sentences that are front-loaded with the core purpose, then add required context (auth requirements, errors, related tool) in a logical order. No extraneous words; every sentence contributes value.

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 has no parameters and no output schema, the description covers the essential information: what it does, prerequisites, error behavior, and a related next step. It omits explicit mention of alternative auth modes, but those are visible in sibling names, so the description is complete enough for effective use.

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?

There are no parameters, so the schema trivially covers 100% of them. The baseline for a zero-parameter tool is 4. The description adds no parameter information because none exists, which 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 a specific action: 'Switch this session's active auth mode to user-session' and the outcome: 'subsequent calls authenticate as a logged-in Ethora user.' This is not a tautology and distinguishes the user-session mode from other auth modes present in the sibling tools (ethora-auth-use-app, ethora-auth-use-b2b), though it does not explicitly name them. It is slightly under the top score because it could have explicitly contrasted with those siblings.

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 gives explicit usage context: it states the prerequisite (login via ethora-user-login storing a user token), the error behavior (downstream 401 until login), and a related next step ('follow with ethora-user-login'). It does not explicitly say when to use this tool vs the app or b2b auth switches, but the provided flow is clear for the user-auth path.

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