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

The description discloses the two authentication workflows (config-based permanent and session-based), and explains that calling with no args returns a link. This adds context beyond the annotations (idempotent, non-destructive) without contradicting them.

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 a single focused paragraph that front-loads the purpose and then explains the two usage modes. No redundant information; every sentence adds 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's relative simplicity (one optional param, no output schema), the description thoroughly explains how to use it, what it does, and the distinction between persistent and session auth. It is complete for an agent to invoke correctly.

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 schema only defines 'token' with no description (0% coverage). The description compensates by explaining that token is a JWT to paste for session login, and that omitting it retrieves a login link. This fully covers the parameter semantics.

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: authenticate by either providing a token or getting a login link. It uses specific verbs ('log in', 'authenticate') and distinguishes itself from siblings (no other auth tools).

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?

Explicitly explains when to use the token vs. no-args mode, and distinguishes permanent vs. session-only login. It also provides the exact call patterns and the recommended approach for permanent connections.

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