Get monthly energy history

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the read-only safety profile is well covered. The description reinforces this with 'Read' and adds the 'this month's' scoping, but does not describe return behavior or other side effects; with annotations present, this is acceptable.

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 short, purposeful sentences with no filler. The action and scope are front-loaded, and the parameter preference is given as a concise, actionable instruction.

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?

For a simple tool with zero required parameters, full schema coverage, an output schema, and strong read-only annotations, nothing needed to invoke it correctly is missing. The scope, parameter preference, and safety profile are all available to the agent.

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 schema covers both parameters at 100%, and the idx schema already states it is 'preferred over name when known.' The description's 'Preferred: idx' mostly echoes the schema rather than adding new semantic information, so the baseline score of 3 applies.

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 uses a specific verb ('Read') and resource ('counter history') with a clear time scope ('this month's'), making it easy to distinguish from the sibling tools get_daily_energy_history and get_weekly_energy_history. No ambiguity remains about what this tool fetches.

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 clear context: use this tool to read the current month's counter history. It also provides parameter preference ('Preferred: idx'), but it does not explicitly state when not to use it or name the daily/weekly alternatives.

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