Get US Natural Gas Hub Prices

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

Beyond the readOnlyHint annotation, it explains conditional behavior for both call shapes: omitting hub returns all live hubs, while supplying a hub returns latest price, basis, and basis history. It also discloses that hub series differ in depth, warns to check history_days, and states the entitlement requirement and authoritative API response.

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 but every sentence earns its place: purpose, use case, hub list, conditional behavior, data-depth caveat, entitlement requirement, and pointer to opa_get_plans. Information is front-loaded and no sentence is filler.

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 having no output schema, the description covers what the agent needs: what the tool returns in each mode, which hubs are valid, data depth limitations, account entitlement, and a fallback tool for access/pricing. This makes it self-sufficient for correct invocation.

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%, so the baseline is 3, but the description adds meaningful conditional semantics: omitting hub lists all hubs, and supplying one returns history. It also gives concrete past window examples and warns about depth differences, adding value beyond the raw parameter descriptions.

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 opens with a specific action and resource: 'Get US physical natural gas hub prices as basis to Henry Hub' with clear units. It then enumerates the exact hubs covered, which separates it from generic price tools like opa_get_price and opa_get_futures.

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 explicitly states 'Use when the user asks about regional gas prices or hub basis' and lists the relevant hubs, giving clear context for selection. It also routes entitlement questions to opa_get_plans, though it does not enumerate exclusions versus every sibling price tool.

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