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

Annotations already indicate the tool is idempotent and non-destructive. The description adds behavioral context by explaining the browser-based login flow, the option to use a permanent config header, and that calling with no args returns a link. This goes beyond the annotations, though it doesn't specify error handling or invalid token behavior.

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 succinct yet comprehensive, using only two sentences to convey the purpose, two usage modes, and parameter semantics. It is front-loaded with the tool's intent and avoids any fluff, making it highly efficient.

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's simplicity (one optional parameter, no output schema), the description fully covers its usage. It explains both invocation patterns, the distinction between permanent and session logins, and the input parameter. No additional context is needed.

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?

With schema coverage at 0%, the description carries the full burden for explaining the 'token' parameter. It does so clearly: the token is a JWT pasted by the user for session-only login, and omitting it yields a link, which gives the agent enough understanding to decide when to include it.

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, with explicit steps to obtain and provide an access token. It distinguishes from siblings like 'connect' by describing its specific authentication flow, making it unambiguous.

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?

It provides explicit instructions on when and how to use the tool: permanent vs session-only login, calling with 'token' or no args to get a link. This gives clear guidance on the two modes and the exact invocation patterns, which is more than adequate for an agent.

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