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

Beyond the annotations (readOnlyHint, non-destructive), the description discloses important behavioral traits: the estimation method, the data structure ('per-month series (est vs EIA actual once published)'), and a critical limitation ('Demo scope hides the freshest month's estimate'). This is substantial contextual information not captured in the 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 two sentences, front-loaded with the core purpose and units, and every clause adds value. It efficiently conveys the methodology, data series, and demo limitation without redundancy.

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 the absence of parameters and the presence of an output schema (not shown to the agent), the description is remarkably complete. It explains the frequency, units, estimation basis, and a key limitation. It leaves no major ambiguity about what data will be returned.

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 tool has zero parameters, so the schema carries no semantic burden. Per calibration baseline, a tool with 0 params receives a 4. The description does not need to explain parameters; it correctly focuses on the output and methodology.

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 that the tool provides a 'Daily/monthly US dry natural gas production nowcast (Bcf/d)' with specific methodology ('estimated from the year-ago level scaled by a YoY growth trend and anchored to news'). This is specific and distinguishes it from sibling tools like storage nowcast or weather models.

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?

No explicit guidance is given about when to use this tool versus alternatives. The description explains what the tool does but does not mention any alternative tools or exclusion criteria, leaving the agent to infer usage context from the tool name alone.

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