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

The description explicitly discloses the side effects of both login methods (permanent vs. session-only), which is valuable context beyond the annotations. It also provides implementation details like the header format. While the description does not contradict the annotations, it omits specific potential outcomes (e.g., error messages for invalid tokens or failure states), hence not a perfect score.

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 informative but contains some informality and redundancy. The sentence 'MCP.AI for IDE agents (Cursor, etc.)' is useful context, and 'log in in the browser' is slightly awkward. The instructions could be more direct, e.g., 'Log in via the browser and copy the access token.'

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 tool with only one optional parameter, the description thoroughly covers the authentication flow. It explains the two modes (permanent config-based and session-based), the required syntax for both, and the user interaction needed for the session-based flow. This is complete for the tool's described functionality.

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 description explains the parameter by giving an example call `{ token: "<jwt>" }`. However, it does not explicitly state that the parameter should be a JWT string, although the word 'jwt' is mentioned. Since the schema provides no description or type, the description carries the entire burden, and it just meets the minimum viable threshold by providing an example.

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 an IDE agent (like Cursor) to the MCP server. It specifies the core actions (login in browser, copy access token) and mentions the primary input parameter (token). While the title 'authenticate' is generic, the description's reference to 'MCP.AI for IDE agents' provides necessary context. However, it does not explicitly distinguish itself from its sibling tools, though the context makes it the obvious 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?

This is a major strength. It explicitly guides the agent on the ideal path: use the config with a bearer token for permanent access. It then clearly states when to use the token parameter: 'Or paste it here for a session-only login: call with { token: "<jwt>" } after the user pastes...' It also tells the agent what to do if the user provides no arguments, defining the required behavior for both success and no-input scenarios.

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