Connect an E*TRADE account

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

Annotations only flag a non-readonly, open-world, non-idempotent operation; the description adds the genuinely decision-relevant behavior: out-of-band code delivery, no browser redirect, two-hour idle timeout, hard midnight US Eastern expiry, no refresh token, and a background renewal every ninety minutes. That is exactly the context an agent needs to decide whether a re-auth is required.

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?

It is front-loaded with the action and the first-call contract, then layers the expiry mechanics in a logical order. Despite being paragraph-length, every sentence carries operational information; nothing is padding.

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?

With no output schema, the description compensates by stating what the first call returns (an authorization URL) and what the user must do with it, plus the full lifecycle constraints on the resulting token. Nothing an agent needs to invoke or re-invoke this tool correctly is missing.

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 coverage is 100% and the schema already documents verifier's role, so the baseline is 3. The description goes further by explaining the parameter's place in the flow ('which you pass back as `verifier` on a second call') and why it exists (E*TRADE issues the code out-of-band), adding meaning beyond the schema text.

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 first sentence gives a specific verb and resource ('Connect this server to an E*TRADE brokerage account over OAuth 1.0a'), and the rest of the definition makes the two-step handshake unmistakable. An agent can distinguish this from etrade_accounts, etrade_positions, and etrade_disconnect without opening any schema.

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 states exactly when to call with no arguments (to obtain the authorization URL), when to call a second time (to pass back the verifier), and when to call again later ('whenever another E*TRADE tool reports an expired token'). Both the trigger and the sequencing are explicit, leaving nothing to inference.

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