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

Annotations already declare the tool is idempotent and non-destructive. The description adds valuable context: it creates a browser-based login flow, returns a link with no args, accepts a pasted JWT, and distinguishes permanent vs session-scoped authentication. It does not fully describe error handling or the exact response shape, but the additional behavioral detail is meaningful.

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 two sentences and front-loaded with context. It is information-dense, but the second sentence is a single run-on with and-d or-splitting three possibilities; it could be slightly clearer with bullet points, but overall it is efficient and without fluff.

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 has one optional parameter and no output schema, the description sufficiently covers the authentication flow, both token modes, and the recommended permanent configuration. It does not mention failure scenarios (e.g., invalid token), but the essential information for an agent to use the tool is present.

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, but the tool explains that the token is a JWT pasted by the user, that it is optional (since no args produces a link), and that it provides session-only access. This compensates well for the 0% schema description coverage.

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: authenticate a user for MCP.AI server by logging in via browser and retrieving an access token. It also differentiates between permanent config-based access and session-only token-based access, making it distinct from siblings like 'connect' or 'marketplace'.

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 explicit instructions on when to use each mode: no args to receive the login link, with a pasted token for session-only login, and recommends the config-header approach for permanent access. This clearly guides the agent on the appropriate invocation context.

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