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

The description adds behavioral context beyond the annotations: it explains the permanent versus session-scoped nature of authentication and the effect of calling with or without arguments. The annotations already declare idempotent and non-destructive, and the description does not contradict them. It stops short of describing response details or side effects on existing sessions, which could justify a higher score.

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 and front-loaded with the main idea. It contains no fluff, but the sentences are a bit dense and could be split for readability. The formatting with colons and semicolons is acceptable but not ideal.

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?

The description covers the two call modes adequately but does not specify the return format for the token call (only 'get the link' for no args). With no output schema, the agent is left guessing what a successful token authentication returns. For a moderately complex tool with two modes, this is a notable gap.

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 single parameter 'token' is not described in the schema, but the description fully compensates by explaining it as a JWT and showing how to use it ('call with { token: "<jwt>" }'). It also clarifies that calling with no args returns the link. This adds significant meaning beyond the bare schema.

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: to authenticate by either providing a login link or accepting a token. It uses specific verbs like 'log in' and 'call with' and explains the two modes. However, it does not explicitly distinguish itself from sibling tools such as 'connect', so it misses the explicit differentiation that would earn a 5.

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 clear usage context: it explains the recommended permanent setup via config header and the session-only alternative via pasting a token. It also instructs how to get the login link. It does not explicitly mention when not to use the tool or name alternatives, so it lacks the exclusions needed for a 5.

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