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

The description discloses key behaviors such as returning a login link when called with no arguments, accepting a JWT for session login, and differentiating permanent vs session credentials. This adds context beyond the annotations (idempotentHint, readOnlyHint) about side effects and persistence. It could mention rate limits or errors, but for an auth flow it is fairly transparent.

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 functional but somewhat run-on and mixes instructions for the agent and user. It could be broken into clearer bullet points or separated by flow. Still, it is relatively short and avoids fluff.

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 an authentication tool, the description covers the essential contexts: how to get a login link, how to pass a token, and the distinction between permanent and session logins. It also suggests a security-best-practice (config header). No output schema exists, so the missing return-value documentation is acceptable. Slight gap: no mention of what happens upon successful authentication (e.g., confirmation or errors).

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?

Although the schema has zero description coverage, the tool description explicitly explains the 'token' parameter: it is a JWT to be passed after the user pastes it. It also clarifies that omitting the parameter retrieves a login link. This compensates well for the schema's lack of detail.

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 this tool handles authentication by providing a login link or accepting a token. It distinguishes between permanent (config header) and session (token) authentication, which clarifies its purpose among siblings like 'connect' and 'marketplace'. However, the phrasing is somewhat cluttered and could be more direct.

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 explains when to use the tool (with no args for a link, or with a token for session login) and even suggests a best practice (config header). However, it does not explicitly compare itself to alternatives or state when not to use it, leaving some ambiguity about its relationship to sibling tools.

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