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

Annotations already cover the safety profile (readOnly, idempotent, openWorld), yet the description still adds substantive behavior: a 7-day cap, SGD denomination, EVS-supplied dates with no time zone, possible missing recent days, and a meter-type restriction. Nothing contradicts the annotations; the only gap is no mention of pagination or error behavior for invalid meter IDs.

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?

Purpose is front-loaded in the first clause, and each following sentence delivers distinct, non-redundant information: currency, date semantics with the missing-days caveat, then the meter-type exclusion. No filler or restatement of the name.

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 one-parameter read tool with an output schema, the definition covers scope, units, temporal semantics, data-quality caveats, and eligibility. It is nearly complete; only error/failure behavior for an unknown or unsupported meter is left unstated.

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% and there is a single pattern-constrained parameter, so the schema carries the documentation load; baseline 3 applies. The description adds only a mild framing constraint (the meter is an NUS meter, not any 8-digit EVS ID) without extending the ID format or behavior.

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?

Names a specific verb and resource ('Get up to 7 days of usage for an NUS meter') and enumerates the return contents: spending analysis, month-to-date spending, balance longevity. It implicitly separates itself from get_meter_balance/get_recent_topups via the usage-vs-balance distinction, but never names a sibling explicitly.

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?

Provides one hard exclusion, 'Not available for SUTD meters', and warns that recent days may be missing. It gives no positive routing guidance telling the agent when to reach for this tool versus get_meter_balance or get_recent_topups, so selection still requires inference.

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