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

The description goes beyond annotations by explaining the key behavioral difference between permanent config-based auth and session-only token-based auth, and by specifying that no-args calls return a login link. It does not describe possible failure modes or token validation behavior, but the main runtime behavior is adequately 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 compact and information-dense, with each sentence contributing a distinct mode or constraint. Minor awkward phrasing like 'log in in the browser' and the relatively long semicolon-heavy final sentence prevent it from being perfectly polished.

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 single-optional-parameter authentication tool, the description covers the main invocation paths and the permanent-vs-session distinction well. It does not state what response or side effect follows a token-backed call, but its simplicity and the no-args 'get the link' behavior make the tool reasonably 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 input schema only declares an optional string token with no description (0% schema coverage), so the description carries the full burden. The description fully compensates by explaining the token is a JWT/access token, when to pass it, and that omitting it will return the login link.

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 identifies this as the MCP.AI authentication/login tool: log in in the browser, copy the access token, and provide it via configuration or a token parameter. It does not explicitly contrast with a sibling tool, so it falls just short of the highest bar for purpose differentiation.

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 explicit usage modes: add the token to server config for a permanent non-expiring connection, or paste the token into this tool for a session-only login, or call with no arguments to get the login link. It also tells the agent when to call with token vs. no args, which is strong practical guidance.

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