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

Annotations already cover read-only/idempotent/open-world safety, so the bar is lower; the description still adds real behavioral context by stating it returns no prices, that with no arguments it returns the variable list and rationale, and that prices live in an external calculator. It does not discuss rate limits or data freshness, so a 4 rather than 5.

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 front-loaded English sentence carries the trigger, scope, and the key negative (no prices) before the Hebrew restatement. It is somewhat long due to the bilingual duplication, but every sentence contributes information and nothing is buried.

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 an output schema present, the description needn't explain return shape, and it covers invocation modes, the absence of prices, and the redirect for real prices. Complete for an agent to call correctly; only minor gaps such as error behavior when neither plate nor make/model is supplied.

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%, making 3 the baseline, but the description adds mode-level semantics beyond the schema: that 'plate' is an alternative lookup key to the make/model/year combination, and that 'year' is optional within that combination. This meaningfully clarifies how the four parameters combine.

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 ('explain what compulsory insurance (ביטוח חובה) price depends on'), and explicitly scopes what is returned ('the regulator's pricing variables', 'Returns NO prices'). It is clearly distinguishable from siblings like lookup_vehicle or explain_licence_fee, which concern different artifacts.

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 the person asks what their compulsory insurance price depends on') and spells out three invocation modes: by plate, by make+model+optional year, or with no arguments. It also redirects to the external regulator calculator for actual prices, but names no sibling tool as an alternative, so it stops short of full exclusion guidance.

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