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

Annotations already indicate idempotentHint: true, and the description additionally discloses that calling with no args returns a browser link, that the token is a JWT for session-only login, and that the recommended config approach works for a permanent non-expiring connection. It also notes the process (user pastes token). This provides rich behavioral context beyond what annotations state.

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 concise and front-loaded with the purpose, then provides key usage details in three sentences. Every sentence earns its place: purpose, permanent method, session method. No fluff or repetition.

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 is a simple authentication with one optional parameter, no output schema, but annotations provide idempotency and non-destructive hints, the description fully covers the needed context: how to initiate login, permanent vs. session options, and expected input. The complexity is low and the description addresses all critical aspects.

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 one optional parameter 'token' with no description, so schema coverage is 0%. The description compensates by explaining that token should be passed after user pastes it, provides the format { token: "<jwt>" }, and clarifies that no args yields the link. It doesn't detail token format beyond JWT, but for a single optional param this is adequate.

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 what the tool does: it authenticates the agent with MCP.AI by either providing a login link or accepting a token for session-only login. It also actively points to a better alternative (adding Authorization header to config) for permanent access. This distinguishes it from sibling tools like marketplace or toolkit_info, as it's specifically the authentication entry point.

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 guidance: it suggests the preferred method (config header) and when to use the session token, and explains the no-args behavior (get link). It even contrasts with the alternative of permanent configuration, providing clear decision-making context for the agent.

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