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

No annotations are provided, so the description carries the full burden. It usefully discloses the billing cost ('5 point per returned record'), which is real behavioral context beyond structured fields, but says nothing about auth requirements, error behavior for unknown numbers, or whether the call is read-only.

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 covering purpose, source, key, and returned fields, plus a short cost note. Efficient with no filler, though the long field enumeration could be tightened.

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 helpfully enumerates the returned fields (names, status, registration date, address, type, liability, purpose, last annual report year) and notes the cost, so an agent knows what it gets back. The only gap is error/not-found behavior for an invalid company number.

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% and the single parameter already documents format, Hebrew label, and an example. The description's 'by company number' merely restates the schema, adding no new syntax or constraint information. Baseline 3 is appropriate.

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 ('Get one company from the Israel registry (Corporations Authority)') and the lookup key ('by company number'). The singular 'one company' plus the field list clearly separates it from the sibling run_il_companies_search.

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 phrase 'by company number' implies the caller must already have an identifier, which suggests using the search sibling when they don't. However, run_il_companies_search is never named and no explicit when/when-not guidance is given, so the routing is left to inference.

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