top_emitters

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

With no annotations, the description carries the full burden and does well: it discloses the default year ('latest year with verified emissions, 2025 in the 2026-09-24 snapshot'), the 1-100 limit with default 10, the fact that derived totals are computed, and that compliance code only exists for 2021-2024. It does not discuss data source freshness limits or permissions, keeping it short of a 5.

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 the default year, then the return fields. The return-field enumeration is long but justified because no output schema exists. Slightly dense but no filler sentences.

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 filtered ranking tool with no output schema and no annotations, the description covers purpose, defaults, filters, return fields, derived values, and the compliance-code year caveat. An agent has everything needed to call and interpret it.

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 50% (country and activity documented in schema, year and limit not), so the description must compensate for the gaps – and it does, explaining the year default behavior and the limit range/default. The activity-code hint about passing codes explicitly also adds meaning beyond the schema, though country filtering semantics are left entirely to the schema.

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?

States a specific verb and resource: installations ranked by verified emissions over a chosen year, with optional country/activity filters. It is clear and distinctive (a ranking, not a general search), but it never names or contrasts with the sibling search_installations, leaving sibling differentiation to inference.

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?

Offers some implied usage context – filters are optional, and 'pass codes explicitly for a wider sector' hints at how to broaden results. However it never states when to prefer this ranking tool over search_installations or installation_history, so the when-to-use guidance remains implicit.

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