Meter reading over a period

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

Goes beyond readOnlyHint and openWorldHint by explaining the nearest-reading computation, inclusion of _start/_end readings, and that only accumulating properties appear, providing valuable behavioral insights.

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?

Packs significant detail into a single paragraph; efficient but could benefit from bullet points for quick scanning.

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?

Covers key aspects: computation logic, output structure, and source filtering, but omits details on result limits, error handling, or timezone specifics given the absence of output schema.

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?

Adds meaningful context beyond schema: node-local dates, inclusive/exclusive boundaries, example demo node ID, and behavior when sourceId is omitted, fully compensating for high schema coverage.

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 it computes a meter-style difference for accumulating properties over a date range, distinguishing it from siblings like query_datum or get_latest by focusing on totals for a period.

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 gives context (e.g., 'natural fit for total for June') but does not explicitly compare to siblings or state when not to use it, leaving some ambiguity.

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