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

With no annotations, the description carries the full behavioral burden. It does add two genuinely useful facts beyond the schema — the upstream data source (Zefix UID register) and a per-call cost of $0.25 USDC — but it omits whether the lookup is a pure read, how multiple supplied identifiers combine, and what happens on no-match or multiple-match.

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 front-loaded sentence plus a cost note, with zero filler — the resource, source, key options, and example all arrive immediately. The brevity is close to the right tradeoff, though the cost clause could arguably be one clause longer if it bought clarity on parameter combination.

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 7-parameter tool with no annotations, no output schema, and no required fields declared, the description is too thin to call safely — an agent cannot determine which parameter combination to prefer or what a result contains. The pricing and data-source disclosures are helpful but do not close the gap on parameter and result semantics.

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 0% across 7 parameters, so the description must compensate and only partly does: it explains uid/che, ehraid, and name as alternative lookup keys, but leaves q, limit, and number entirely unexplained. It also never says whether the keys are OR'd or AND'd, which is the single most important semantic for a 7-param all-optional lookup.

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 names a specific verb and resource — Swiss company lookup via Zefix (UID register) — and gives a concrete UID example (CHE-105.909.036), which distinguishes it from the many non-Swiss company siblings (uk_company, au_company, fr_company). It does not explicitly name those siblings, but the jurisdiction qualifier does the differentiation work.

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 guidance on when to use this versus company_full, company_research, kyb_report, lei_lookup, or registry_batch, all of which overlap in the entity-lookup space. The agent is left to infer that this is the cheap single-entity Swiss lookup, but nothing in the text states when-not to use it or what a fuller alternative provides.

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