get_trading_cost_estimate

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

Annotations already declare readOnlyHint=true, so the description's 'without placing it' is consistent. It adds value by detailing the return format and a dedicated rate limit (20 requests/60s), but lacks information on error handling or permissions.

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?

Two sentences, front-loaded with purpose, followed by concise details on arguments and return. No wasted words; every sentence adds essential information.

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?

Given 11 parameters and output schema existence, the description covers argument constraints, return structure, and rate limit. It does not mention authentication or prerequisites, but the read-only nature reduces need. Could elaborate on usage scenarios.

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 coverage is 100%, baseline 3. The description adds the constraint 'exactly one of symbol/instrument_id and exactly one of amount/units/contracts', which clarifies the otherwise optional schema entries. This improves parameter understanding.

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 clearly states the verb 'estimate' and the resource 'costs of a hypothetical open order'. It distinguishes itself from create_order (a sibling-like tool) by emphasizing it does not place the order, making the purpose specific and 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 implies usage before placing an order ('without placing it') and references create_order arguments, but does not explicitly state when to avoid this tool or compare to other cost-related tools among siblings.

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