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

With no annotations, the description carries the full burden of behavioral disclosure. It reveals that the tool is free, requires proof of npub ownership, and explains the anti-DOS rationale. It also clarifies that a 'pending' check_oauth_status does not indicate a lapsed session. These details go well beyond a basic function statement and provide security-conscious transparency.

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 well-structured and front-loaded with the purpose. It contains several sentences of necessary guidance (flow, security, usage conditions). While slightly verbose, each sentence earns its place and avoids redundancy. It is not excessively long for the complexity of the OAuth flow.

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 complexity of an OAuth flow and the presence of an output schema, the description is remarkably complete. It covers the authorization URL, the follow-up step, cost, security/privacy considerations, and when to invoke the tool. The mention of 'upstream_auth_refresh_needed' and the pending-status caveat addresses edge cases, making this fully sufficient for an agent to use correctly.

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?

Schema description coverage is 100%, so the baseline is 3. The description adds no new details about parameter syntax or semantics beyond what the schema already documents. It mentions using the 'same npub' but the schema already defines both parameters comprehensively. The description does not need to compensate, thus a 3 is appropriate.

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 opens with a clear action verb and resource: 'Start the OAuth2 authorization flow.' It unambiguously states the tool's primary function and distinguishes it from the related 'check_oauth_status' by explaining the sequential relationship. This exceeds a vague purpose statement and clearly differentiates from sibling tools.

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 provides explicit when-to-use and when-not-to-use instructions: 'Do NOT call this pre-emptively... attempt the live tool call first and only begin OAuth when it fails with upstream_auth_refresh_needed.' It also names the alternative (check_oauth_status) and explains the completion flow, offering strong guidance.

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