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

With no annotations provided, the description carries the disclosure burden and does meaningful work: code lookups return title, level, parents and children; text queries return a deterministic word-match ranking explicitly noted as 'no LLM'; and the data is 'offline tables' so results are stable. It does not describe empty-result or ambiguous-match behavior, which keeps it out of 5 territory.

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 sentences, front-loaded with the triggering condition, then the system inventory, then the return/ranking behavior. Dense but every clause carries information; a minor cost is that the system inventory reads like a reference block rather than prose.

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 5-parameter lookup tool with no output schema and no annotations, the description covers both query modes, the four systems with their formats, and a sketch of the return shape (title, level, parents, children, ranked matches). The remaining gap is that with zero required parameters it does not state that at least one of `code`/`query`/`items` is needed.

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 100%, so the baseline is 3; the description adds genuine value beyond it by giving per-system code formats and lengths (NAICS 2–6 digits/Census Bureau, CPV 8 digits/Publications Office, SCIAN Spanish titles, NACE ISIC-compatible at division and group level), which compensates for the absence of an enum on the `system` parameter. It does not clarify that code, query, or items must be supplied, but the format guidance is a real addition.

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 verb+resource (look up industry/procurement codes and their official titles/hierarchy) and enumerates the exact code systems covered (NAICS 2022, NACE Rev. 2.1, CPV 2008, SCIAN 2023). It distinguishes itself from the sibling lookup_hs_code by scope (industry/classification codes, not goods codes) and covers both the code→description and text→code directions.

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 explicit trigger phrasing ('Use this when you need the industry or procurement code for an activity, product or service, or the official title and hierarchy of a code') plus concrete downstream use cases (supplier classification, KYC, tenders, statistics). It never names a sibling alternative or states when not to use it, so it falls short of a 5.

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