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

The description explains behavioral aspects beyond annotations: it clarifies that the tool can either return a login link (when called without token) or accept a token to complete authentication. It also contrasts permanent vs session-only modes. It does not contradict the idempotentHint annotation, but it omits details about response format and potential errors, leaving some gaps.

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 composed of three dense sentences with no fluff. It front-loads the core purpose and then details usage patterns. It is slightly longer than necessary but each part adds value, so it earns a 4 rather than 5.

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 lack of an output schema, the description covers the main workflow and parameter usage well. However, it does not describe the expected result of a successful login (e.g., confirmation message or stored state), nor any error conditions (like invalid token). For a simple auth tool, it's fairly complete, but additional outcome details would push it to 5.

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 an optional 'token' string with no description, but the tool description fully explains its meaning: passing a JWT token initiates login, and omitting it returns a link. This adds complete semantic meaning beyond the 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 states the tool authenticates to MCP.AI, with specific verb 'log in' and resource 'MCP.AI', and distinguishes from sibling tools like connect and marketplace by focusing on token acquisition and login flow.

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 usage instructions: the best practice of adding the token to the server config for a permanent connection, and the alternative of passing the token as a parameter for session-only login, plus how to call with no args to get the link. This clearly defines when and how to use the tool.

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