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

Beyond annotations (which indicate idempotent, non-read-only, non-destructive), the description explains behavioral traits: no args returns a login link, passing a token establishes a session, and config header creates a permanent non-expiring connection. It discloses the flow and token semantics, adding meaningful context beyond the annotations.

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, front-loaded with purpose, and every sentence earns its place. It efficiently covers the auth flow, permanent vs. session options, and token usage without redundancy.

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 tool with one optional parameter and no output schema, the description is complete. It explains how to use both invocation modes, what to expect when no token is passed, and the recommended permanent setup. No critical information is missing.

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 only defines a single token string with no description, but the description fully compensates by explaining that token is a JWT to be pasted after user login, that it is optional, and that omitting it yields a link. This adds critical meaning that the schema lacks.

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 for IDE agents (Cursor, etc.). It uses specific verbs and resource ('log in', 'access token') and differentiates itself from siblings by describing the browser-based login flow and the optional token parameter. The purpose is unmistakable.

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, including two distinct usage paths: permanent connection via config header with Authorization: Bearer, and session-only login by passing a JWT token. It also specifies calling with no args to get the link, giving clear alternatives and context for each mode.

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