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

Annotations already cover read-only safety, but the description adds real behavior: nothing is fetched, no order is placed, a text summary plus botspot.trade link is always returned, and an interactive panel renders only on MCP Apps hosts. It does not mention input limits (max 8 legs) or what happens with malformed legs, which keeps it from a 5.

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?

Front-loaded with the user question the tool answers, then scope, then output shape — good ordering and no filler. The standalone "Read-only." sentence largely restates the annotations, a small redundancy.

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?

Covers purpose, scope, and return surface (P&L curve, breakevens, text summary, link) for a tool with no output schema and a fairly complex nested input. It leaves half the top-level parameters semantically undefined, which is the main remaining gap.

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 0%, so the description carries the burden. It does define the leg fields well ("call or put, long or short, strike, premium, contracts"), but underlying, expiration, fees, priceRange, underlyingPrice, and the leg multiplier are never explained, so it only partially compensates.

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?

States a concrete verb and artifact: computes expiration payoff and breakevens from user-supplied legs. It also bounds scope explicitly ("uses only the inputs given; fetches no data and places no trade"), which cleanly separates it from siblings like get_broker_option_chain or get_broker_positions that pull live data.

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?

Frames the trigger question ("What happens to this option trade at expiration?") and clarifies it operates purely on user-described legs, which tells the agent this is the hypothetical-analysis path rather than a broker data path. No sibling is named as an alternative and no exclusion is stated explicitly, so it stops short of full routing guidance.

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