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

Adds meaningful behavior beyond annotations: calling with no args returns the login link, while passing a token yields a session-only login. It also differentiates between permanent config-level authentication and temporary in-call authentication, which is useful context. No contradictions with 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 condensed and contains useful detail without filler. It is a single block with somewhat run-on phrasing, but every sentence earns its place and the 'Best:'/'Or' structure makes the alternatives clear.

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-parameter auth tool, it covers both storage of a permanent token and a session-based fallback. It explains the no-args behavior and the token-passing behavior sufficiently for an agent, though it does not describe invalid-token handling or explicitly compare to sibling 'connect'.

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 'token' as a string with no description, so the description fully compensates. It explicitly says the token is a JWT, that it is optional, and that when passed it enables session-only login, while omitting it retrieves the link.

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 identifies this as an authentication tool for MCP.AI in IDE agents, instructing the user to 'log in in the browser, copy the access token.' It also explains the two invocation modes: with a token for session login or no args to get the login link. It doesn't explicitly contrast with sibling 'connect', so it stops short of 5.

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?

Provides explicit usage guidance and alternatives: the 'best' method is adding an Authorization header to the server config for permanent access, while passing a token provides a session-only login. It is clear for whom this tool is intended ('for IDE agents, etc.') but lacks explicit exclusions or distinctions from sibling tools.

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