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

Annotations already declare readOnly=true, destructive=false and idempotent=false, so the safety profile is covered. The description adds genuinely non-derivable context: the credit cost per successful call, that repeated calls may bill again, and an untrusted-data warning — consistent with idempotentHint=false. It still says nothing about what the response contains or any rate/coverage limits.

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?

Four short sentences with zero filler, and the core purpose is front-loaded before the cost and trust caveats. Every sentence contributes actionable information.

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 sitting among dozens of overlapping market-analytics siblings with no output schema, the description should at least sketch what the concentration output looks like and when it beats amazon_market_statistics or amazon_market_research. The cost/trust caveats are present, but the selection context is not.

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%, so the schema already carries the parameter burden (including the note that newProduct is accepted for compatibility only). The description adds no parameter-level meaning at all — notably no hint about how nodeIdPath, asins, or topN interact with the concentration measure. Baseline 3 applies.

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: 'Measure product concentration within an Amazon category.' This is more precise than a bare 'get goods' and implies a concentration metric (CR-n/HHI-style) over a category node. It does not, however, distinguish this from adjacent siblings such as amazon_market_statistics, amazon_market_research, or amazon_market_brand, which an agent must choose between.

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 gives no when-to-use guidance, no prerequisites (e.g. needing a category nodeIdPath from amazon_product_node), and no alternatives for the many amazon_market_* siblings. The only actionable instruction concerns cost, not selection.

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