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

The description goes beyond the annotations by explaining two key behaviors: returning a browser link when called with no args and accepting a JWT token to establish a session. It also adds context about permanent, non-expiring vs. session-only authentication. The main omission is a clear statement of what happens on success or failure, but the existing disclosure is still solid.

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 packs multiple pieces of information into a single paragraph but remains dense without redundancy. The structure could be improved with clearer separation between the config-based method, the session-based method, and the no-argument shortcut, but no sentence is wasted.

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 with no output schema, the description gives a usable workflow: when to call with a token, when to call without, and how to configure a permanent connection. It does not explicitly describe the response format beyond 'get the link', but the overall guidance is sufficient for an agent to invoke the tool 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?

Despite the input schema having only a bare token property with zero description coverage, the description fully explains the token's meaning and how the caller should supply it. It distinguishes between pasting the token as { token: '<jwt>' } and omitting it to receive the login link. This completely compensates for the missing 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's purpose: authenticating to MCP.AI by logging in in the browser and obtaining an access token. It specifies the main resource (MCP.AI) and distinguishes the tool from unrelated siblings like marketplace or show_version. The verb 'log in' and the authentication flow leave no ambiguity.

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: adding the token to server config for a permanent connection, or passing a token for session-only login. It also explains that calling with no arguments returns the login link, providing a clear decision path for the agent. This is strong usage guidance even without naming sibling alternatives.

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