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

Annotations already mark the operation read-only and idempotent; the description adds substantial behavioral detail beyond that: derivation thresholds (80%/120%), same-interface/band/type constraints, the exclusion of the source product from the search, and the A/B/C grouping. It also warns that equal figures do not make a drop-in replacement and that interfaces must be confirmed with the manufacturer.

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 dense but well organized: core purpose and method first, then returns, then when to use, then a safety caveat. Every sentence carries distinct information and none is filler.

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 complex tool with no output schema, the description explains what is returned (derived requirements, non-compared fields, groups A/B/C), when to use it, and the critical interface caveat. The schema covers all parameters, so nothing an agent needs to invoke it correctly is missing.

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 baseline is 3. The description adds general context around deriving requirements from a product's published values and searching its class, but it does not add parameter-specific meaning beyond the schema's already complete descriptions.

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 action ('Alternatives / second sources / replacements') and a precise scope ('for ONE product'), then explains the derivation method and output groups. This clearly separates it from sibling tools such as find_suppliers or match_components without needing to open their schemas.

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?

It gives an explicit trigger: 'Use when a part has a long lead time, is discontinued or export-restricted.' It does not name alternative tools or state exclusions, so it falls just short of full 5-level routing guidance.

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