Estimated dealer gamma exposure

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

Beyond the readOnlyHint and openWorldHint annotations, the description discloses critical behavioral details: the Black-Scholes estimation assumptions (zero rate, zero dividend, implied volatility from EOD), the dealer convention (long calls, short puts), the null flip handling (flip_status values and their meaning), and data freshness ('Reads the prior session's settled open interest'). This goes far beyond annotations.

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 dense and every sentence adds distinct value, but it is somewhat lengthy for a single tool. It is front-loaded with the core purpose and then unfolds limitations and usage nuance. No waste, but the length itself slightly reduces conciseness.

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?

Despite lacking an output schema, the description covers the key output concepts (net/gross GEX, flip status, as_of/spot_date), error conditions, and limitations. It is comprehensive for a tool of moderate complexity, giving the agent sufficient context to set expectations and invoke correctly.

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 input schema already documents both parameters (symbol and by_strike) with clear descriptions, achieving 100% coverage. The description adds extra value by explaining the by_strike parameter's size implications ('Large; only request it when the user wants strike detail') and reinforcing the symbol scope ('US listed stocks and ETFs only'). This is a meaningful enhancement over schema alone, though not exhaustive.

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 uses a specific verb phrase ('Estimated dealer gamma exposure') and clearly defines the resource ('US listed stock or ETF') with concrete outputs (net/gross GEX, zero gamma flip level, heaviest strikes). It explicitly contrasts itself with sibling tool max pain, making differentiation unambiguous.

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 provides explicit usage boundaries: 'Unlike max pain this is a Black-Scholes ESTIMATE', states exclusions ('cash-settled index options (SPX, NDX, RUT, VIX) return an error — use SPY, QQQ, IWM instead'), and warns about intraday limitations ('cannot update intraday'). It also advises when to request by_strike ('only request it when the user wants strike detail').

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