preflight_buy_event_contract

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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description adds meaningful behavior beyond that: it is a DAY limit buy, the response contains the limit price used and a preflight estimate including commission and exchange fee, and no order is placed. The fallback lookup behavior for limit_price is also disclosed.

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 with the core purpose and the no-order guarantee, then provides a compact Args section. Despite being somewhat long, every sentence adds necessary detail given zero schema parameter descriptions.

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?

It is complete for a preflight pricing tool: it explains the operation, the limit-order semantics, the response contents, the no-order guarantee, and every parameter despite the schema having no descriptions. The existence of an output schema means it need not fully detail the return object.

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 full burden and does so well. It documents all five parameters: contract symbol format and side convention, quantity precision and default, limit price range and fallback behavior, event_symbol dependency when limit_price is omitted, and account_id environment fallback.

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 verb and resource: price a buy of an event contract on the YES or NO side without placing it. It distinguishes itself from order-placement siblings by explicitly saying it does NOT place an order, and even warns against using the '-EVENTCONTRACT' symbol used by get_event_contract_bars.

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 establishes the preflight use case and says no order is placed, which implicitly positions buy_event_contract as the execution alternative. However, it does not explicitly name buy_event_contract or explain exclusions such as when to use preflight_order instead.

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