operator_concentration

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

Annotations already indicate readOnlyHint=true. The description adds marketplace scope (Amazon US/UK), return format, and filter behavior. No contradictions; useful context beyond annotations.

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?

The description is a single paragraph that efficiently conveys purpose, usage, and parameters. It is front-loaded with the core function. Could benefit from bullet points for filters, but not excessively long.

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 explains the return values (HHI, label, top operators). It covers marketplaces and filter details. Leaves minor gaps (e.g., error handling, exact response structure) but is largely sufficient for a 12-parameter tool.

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 42% (low). The description explains several filters (min/max HHI, operator, operator_contains, share_pct, listings_controlled) beyond the schema. However, it does not cover all 12 parameters (e.g., limit is omitted), so it provides partial but meaningful improvement.

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 clearly states the tool computes HHI concentration across ASINs or a brand's catalog, revealing operator control of listings. It specifies the returned data (HHI, label, top operators) and differentiates from sibling tools like operator_category_dominance by focusing on concentration index.

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?

The description provides explicit use cases (private-label fragmentation checks) and mentions optional filters. It does not explicitly name alternatives or when-not-to-use, but the context is sufficiently clear for an agent to decide.

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