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

Annotations already mark the tool as idempotent and non-destructive, but the description adds valuable behavioral context: the token is a JWT, the config-header approach gives a non-expiring connection, and pasting a token provides only a session-level login. It also explains the no-arg call returns a link. This goes beyond the annotations, though it does not cover side effects like invalidating previous sessions or error handling.

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 sentences that are information-dense and well-structured: purpose, recommended permanent approach, and session-only alternative. It is somewhat verbose but every sentence adds necessary detail, and the core information 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?

For a simple one-optional-parameter tool with no output schema, the description covers usage modes well. However, it omits what the tool actually returns in each case (e.g., success message, session state, or error conditions). Since there is no output schema to fill this gap, the description is incomplete on return value semantics.

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 provides no description for the 'token' parameter (0% coverage), so the description must compensate. It does so by explaining that 'token' is a JWT copied from the browser, and that omitting it (no args) returns the auth link. This gives the parameter meaning and clarifies optionality, fully compensating for the schema gap.

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 purpose: authenticating via browser login and copying an access token, with two distinct modes (permanent config header vs session token). This makes the function specific. However, it does not explicitly differentiate from sibling tools like 'connect', so it doesn't fully meet the high bar for distinction.

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 explicit usage guidance: for permanent authentication, add the token as an Authorization header in the server config; for session-only login, call with a token argument or no arguments to get a link. This clearly indicates when to use each form of invocation, though it does not mention when to avoid this tool or compare it to alternatives.

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