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

The description discloses the return behavior (no args gives a link) and the side effects (permanent vs session login). It complements the annotations (idempotent, non-destructive) by explaining the practical implications. It doesn't explicitly mention failure cases (e.g., invalid token), but this is not critical for usage.

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 despite covering multiple scenarios. It uses clear separators (e.g., 'Best:', 'Or') to structure the instructions, making it easy to follow without unnecessary verbosity. Slightly longer than minimal, but every sentence adds value.

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?

The description provides sufficient context for both usage patterns, including outcomes and configuration options. It does not describe the exact output format (e.g., JSON structure), but since no output schema is defined, this is acceptable. It fully addresses the tool's purpose and parameter behavior.

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 only parameter 'token' is fully explained: it is the access token to be used for authentication. The description specifies that providing it completes the login, while omitting it returns a link. This adds meaning beyond the schema's bare type definition.

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 function: to authenticate a user by providing a login link and accepting an access token. It distinguishes itself by explaining the two modes (permanent config vs. session-only) and the args behavior, which is more specific than sibling tools 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 explicitly explains when and how to use the tool: call with no args to get a login link, or with a token to authenticate. It also clarifies the difference between permanent and session-only authentication, giving clear instructions for both scenarios.

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