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

The description discloses that the token can be stored permanently in config (non-expiring) or used for a session, and that calling without args returns a login link. This goes beyond the annotations, which only indicate idempotency and non-destructiveness.

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 two sentences but packs a lot of information. It's front-loaded with the purpose, then gives actionable steps. While slightly dense, it remains clear and not verbose.

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 authentication tool with one optional parameter, the description covers the main workflow and both token storage options. It mentions the login link but doesn't detail the response format; however, given the simplicity, it's sufficiently complete.

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 has only a 'token' string with no description. The description explains that token is a JWT to paste for session-only login, and that it can be omitted to retrieve the login link, fully compensating for the lack of schema documentation.

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 is for authentication, describing the browser login flow and token retrieval. It distinguishes between permanent and session-only login modes, making its purpose unambiguous.

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?

It provides explicit instructions for two use cases: configuring a permanent token via header vs session-only token passed as parameter, and also explains the no-args call to get the link. This gives clear guidance on when to use each invocation.

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