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

Annotations already indicate idempotent, non-destructive, and non-read-only behavior. The description adds useful context about the browser flow, the permanent config option, and the session-only paste option. However, it does not disclose what happens when an invalid token is passed, whether the token is stored, or what response the tool returns in success/failure cases.

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 three sentences and contains actionable information without fluff. It is dense but slightly cluttered by the embedded code span and multiple conditional instructions; a more structured format (e.g., bullet points) would improve scanability, but it remains acceptably concise.

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?

There is no output schema, so the description must explain return behavior; it only states that calling with no args returns the login link. It does not explain what the tool returns when a token is provided, how errors are surfaced, or the expected success confirmation. For an authentication flow, this is a notable completeness gap, but the core invocation options are covered.

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 lists an optional 'token' string with no description. The description compensates by explaining that the token is a JWT pasted by the user, that it must be passed as { token: "<jwt>" }, and that omitting the argument triggers the login-link behavior. This adds meaningful semantic context beyond the bare schema.

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 communicates that the tool authenticates an MCP.AI session for IDE agents: it provides a browser login link, accepts a pasted JWT token, or instructs users to configure a permanent header. It is specific about the resource (MCP.AI authentication) and the available invocation modes, though it does not explicitly name itself as the authentication action beyond 'log in'.

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 practical usage guidance: adding the token to server config for a permanent connection is recommended, while passing the token in this call is for session-only login; calling with no args returns the login link. This clearly distinguishes when to use each invocation pattern, though it does not mention sibling tools or conditions where authentication might not be needed.

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