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

Beyond the annotations, the description explains that this prepares unsigned transactions, how the payout is triggered, how the move beyond strike times cover is capped by the pool, and the premium approval workflow. The readOnlyHint=true annotation is consistent with preparing unsigned transactions rather than executing them.

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 front-loaded and compact at two sentences, with no obvious filler. However, the first sentence is very dense with semicolon-separated payoff mechanics, making it harder to parse than it needs to be.

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 complex financial preparation tool with no output schema, the description covers timing, payoff direction, cap, premium approval, and that the output is unsigned transactions. It is largely sufficient, though it does not describe the returned transaction structure or any failure/edge cases.

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 schema already defines every parameter including side, symbol, wallet, notional, and strike_bps. The description ties side and strike to the payoff formula, but it largely repeats schema-level meaning rather than adding new per-parameter details.

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 a specific action and resource: 'Unsigned transactions to buy Monday-gap cover on a stock.' It also scopes the timing ('while the market is shut') and the payoff direction, which distinguishes it from siblings such as buy_option or open_short.

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 clearly implies when to use the tool: while the market is shut, until an hour before reopen, and for short versus long gap exposure. It does not explicitly name alternative tools or exclusions, so it falls short of full when/when-not guidance.

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