ibkr_historical_bars

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

The description explicitly labels the operation 'read-only', which aligns with the annotations readOnlyHint=true and destructiveHint=false. It adds mild context by mentioning IBKR Gateway, but does not disclose expected output shape, timezone behavior, or potential connectivity requirements.

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 a single, front-loaded sentence with no wasted words. It conveys the core action, resource, and source in under 15 words.

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?

The schema fully documents all seven parameters, including the nested contract object, so parameter coverage is strong. However, with no output schema, the description does not clarify the response format or any limits, leaving some contextual ambiguity for an agent invoking the tool.

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%, with meaningful defaults and enums already documented for parameters like barSize, whatToShow, and formatDate. The tool description itself adds little parameter-level meaning beyond identifying 'contract' as the target.

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 'Fetch' and the resource 'historical bars for a contract', with the source 'IBKR Gateway' adding specificity. It is easily distinguishable from all sibling tools, none of which retrieve historical bar 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?

The description makes the basic use case clear: fetch historical bars for a contract. However, it provides no explicit guidance on prerequisites such as resolving a contract via search_contracts or contract_details, and no comparison to alternatives, though no sibling tool directly overlaps in purpose.

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