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

Annotations declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds nothing beyond that – no statement about what the facet response contains, whether counts are computed over filtered results, or how pagination interacts with aggregation. With annotations carrying the safety burden, the minimal description leaves a gap but isn't contradictory.

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?

One sentence, no waste, but it is so short that it omits all of the structural information the agent needs (which facet values mean what, how filtering works). Conciseness without compensatory completeness leaves the definition under-specified rather than tight.

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 tool with 20 filter parameters, one required facet dimension, and no description of the return aggregation, one sentence is far too thin. An output schema exists, so return-format explanation isn't strictly needed, but the description should at least explain that aggregation is computed over the filtered result set and confirm the required facet's role. It doesn't.

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 schema enumerates all 8 allowed facet values, so the facet parameter's semantics are fully defined there. The description adds no semantic detail beyond the schema – not even clarifying which filters interact with the facet. Baseline 3 is appropriate when the schema does all the work.

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 states a specific operation ('facet aggregation') and resource ('SEC companies dataset'), so the purpose is intelligible. But it doesn't distinguish this tool from the numerous other *_facets siblings (e.g. datasets_techstack_facets, datasets_jobs_facets), nor does it distinguish it from datasets_sec_companies_search, which is a close sibling in the same family. Differentiation from siblings is absent.

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?

There is no when-to-use guidance whatsoever: it never says to call this вместо datasets_sec_companies_search when the agent needs counts by industry/exchange/state rather than individual rows, and it never mentions how the facet parameter selects which aggregation dimension to use. Usage is implied only by the family naming convention.

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