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

Annotations already mark the tool as idempotent and non-destructive. The description adds useful behavioral context: the browser login flow, the session-only nature of pasted tokens, and the permanent non-expiring option. It does not elaborate on what the response looks like after a successful token authentication, but this is not required given the simple auth scope.

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 front-loaded with the core purpose, and both permanent and session-only paths fit into one sentence. The phrasing is slightly awkward ('log in in the browser') and could be tightened, but every piece of text earns its place.

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 simple one-optional-parameter authentication tool with no output schema, the description gives enough context to call it correctly: browser login, token paste, no-args link retrieval, and permanent vs session behavior. It loses a point because it never states what the tool returns after a token-based call or how failures surface.

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 defines 'token' as a string with zero description coverage. The description compensates fully by identifying the token as a JWT, showing the exact call shape ({ token: "<jwt>" }), and clarifying that omitting it returns the link. This is exactly the meaning an agent needs.

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 that this tool authenticates MCP.AI for IDE agents and explains the browser/token flow. It gives specific instructions ('log in in the browser, copy the access token') and distinguishes this from the other tools by making the authentication scope explicit.

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 provides explicit when-to-use guidance: use the config header for a permanent connection or paste the token for a session-only login. It also explains the no-args call path to obtain the link, leaving no ambiguity about the available invocation modes.

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