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

The description is transparent about side effects: it may open a browser, it implies a state change (authentication). It clearly states the token is non-expiring when set in config vs. session-only when passed as an argument. However, it doesn't mention rate limits or side effects on subsequent calls, but given annotations already mark it as idempotent and non-destructive, the description adds good context.

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 compact and informative, packing a lot of information into two sentences. It uses abbreviations and parentheticals effectively. It could be slightly restructured for clarity, but it's quite concise.

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 covers the main use cases and alternatives well. It could mention what happens after a successful login (e.g., 'you are now authenticated for the session') or if there are any post-conditions, but it's not strictly necessary. The description is nearly complete for an authentication tool.

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 parameter `token` is not described in the schema, but the description explains its semantics well: 'call with { token: "<jwt>" } after the user pastes'. This directly compensates for the 0% schema coverage. However, it's not entirely comprehensive about edge cases, but it's sufficient.

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: to authenticate by logging in via browser and copying an access token. It also explains the two modes (session-only vs. permanent via config). However, it could more explicitly say 'authenticates the user' as its primary function, though it's strongly implied.

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 explicitly tells when to use this tool (for IDE agents like Cursor) and precisely how to use it in each scenario (with no args, with token, or via config header). It even mentions an alternative (adding to config) for a permanent connection, which differentiates the usage.

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