Fold3 session

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

Annotations already declare idempotentHint=true and destructiveHint=false, and the description adds context: login uses the saved Ancestry session, has no browser or password interaction, and status reports signed-in status, account type, and premium access. This goes beyond the annotations by explaining the mechanism and prerequisites, though it doesn't detail failure modes or side effects of repeated logins.

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, concise and front-loaded with the core purpose. It explains both actions and provides a critical usage note without redundancy. Minor inefficiency: the phrase 'The Fold3 sign-in' could be more precise, but overall it's well-structured and every sentence earns its place.

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?

For a session-management tool with a single parameter, the description covers the essential return values for status, the login mechanism, and the prerequisite. It does not have an output schema, but it adequately describes what the agent can expect. The note about login being rarely called directly fills a practical gap. Some detail about error handling or idempotency confirmation is absent but not critical.

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 lists the enum values 'status' and 'login' with a terse description. The description enriches these by defining exactly what status returns (signed-in status, account subscription level, premium access) and what login does (signs in via Ancestry session). Since schema coverage is 100% but the enum descriptions are minimal, the description adds meaningful semantic detail.

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 states that this tool manages the Fold3 session, covering 'status' and 'login' actions. It clearly differentiates from sibling tools like fold3_search and fold3_download by focusing on session state rather than data retrieval or downloads. While the opening phrase 'The Fold3 sign-in' is a bit noun-like, the subsequent explanation makes the purpose explicit.

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 says 'Downloads sign in by themselves when needed, so login is rarely called directly,' which tells the agent when not to call login. It also specifies that login requires a valid Ancestry session (via ancestry_session status), giving a clear precondition. This directly addresses when to use status versus login and when to avoid the tool altogether.

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