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

Annotations already declare readOnlyHint/destructiveHint/idempotentHint/openWorldHint, so the bar is lower. The description still adds real value: 'Nothing is deposited or signed by this tool: no key, no transaction,' plus an explanation of the eligibility checks and cost quoting. It's consistent with the annotations, though it doesn't discuss rate limits or how repeated calls interact with the ask-once guidance.

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 trigger condition is correctly front-loaded, but the core is one very long run-on sentence stacking eligibility, sizing, cost, and return behavior in a single clause chain. It is informative but dense and could be split into discrete statements without loss.

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 carries the return-value burden and discharges it ('returns a Go mode link that opens the owner's deposit sheet already filled in'). It also covers the read-only nature and computation steps. Minor gaps remain around quote expiry/volatility of the stated costs and the ask-once constraint's implications.

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 all four parameters are already documented (including the vault maxLine cap on line_usd). The description adds contextual meaning (the deposit is sized at the agent's own LTV with a 23% fall buffer, cost stated per day and per week) but does not map this to individual parameter names or formats. Baseline 3 is appropriate when the schema does the heavy lifting.

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 names a specific action (ask the owner for a stock-backed line), the resource (a Robinhood stock token the owner holds), and the full behavior chain: validates eligibility (price, holds, caps, week's room), sizes the deposit at the agent's LTV, quotes cost, and returns a prefilled 'Go mode' link. This scope is clearly distinguishable from siblings like request_borrow, which do not involve a stock-backed owner deposit.

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 the trigger condition precisely ('When an agent's Priors line is too small for a task') and adds a usage constraint ('Ask once per task, and only for what the task needs'). It stops short of naming an explicit alternative sibling (e.g., request_borrow) or a when-not-to-use case, so it's strong but not fully routing.

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