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

Annotations already mark this read-only, idempotent, non-open-world, but the description adds material behavior beyond them: a double fleet scan that is slow and can time out, exclusion of commissioning/CONTRACTED/TOLLED units from ranking (with the commercial-return rationale), movement against an equal-length prior period, and the caveat to check unit_class and peer_comparable before treating a gap as performance.

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?

Front-loaded with the core purpose and metric definition, then layers caveats, exclusions and the sibling routing in a logical order. It is dense and sentence-heavy, but virtually every clause carries actionable information rather than 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?

With no output schema, the description carries the return contract itself, naming every row field and the movement column, and it covers exclusion semantics, performance caveats, and runtime limits. An agent has everything needed to call and interpret this tool correctly without opening anything else.

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 goes further: it explains what capture_fc_pct vs capture_perfect_pct actually mean, and clarifies that include_arrangement changes whether CONTRACTED/TOLLED units are ranked at all. It does not restate enum/format details already in the schema, so the added meaning is real but not exhaustive.

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?

Opens with a specific verb+resource ('League table of merchant NEM batteries over a date range, ranked by capture rate by default') and defines the two headline metrics precisely (capture_fc_pct as revenue share of forecast-informed benchmark, capture_perfect_pct as share of the perfect-foresight ceiling). It also enumerates the row shape, so the agent knows exactly what it gets back and how it differs from the unit-level sibling get_battery_revenue.

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?

Explicitly routes the agent: 'For one unit's revenue use get_battery_revenue,' which disambiguates against the closest sibling. It also states the practical operating constraint (keep the range to a month or less; can time out on long ranges) and the exclusion condition plus its override (include_arrangement), covering when-not as well as when.

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