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

No annotations are present, so the description must carry behavioral disclosure. It does so well by describing the returned audit envelope (provenance, verification) and the non-failing not_found behavior. It stops short of discussing auth or rate limits, but those are not critical for this tool.

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?

Three focused sentences with no filler: first states what it does, second gives usage guidance, third clarifies error handling. The key behavior is front-loaded.

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?

The description covers purpose, batch behavior, return envelope, and error handling for missing keys. Combined with the schema's key example and max count, an agent has enough to call it correctly. It could additionally point to search_factors for finding valid keys, but that is a minor gap.

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 description coverage is 100%, and the parameter description already explains canonical keys, provides examples, and states the max of 25. The description adds context about batch semantics but does not need to expand parameter meaning further.

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?

Clearly states it looks up several emission factors by key in one call and returns the same audit envelope as lookup_factor. It is explicitly differentiated from the singular sibling lookup_factor.

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?

Directly instructs to use this tool instead of calling lookup_factor in a loop and describes the batch context, e.g., portfolio or multi-country comparison. This gives clear when-to-use guidance and names the alternative.

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