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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, open-world), so credit goes to added context: the validity window 1.4.2026-31.3.2027, that the price group is fixed at first registration, that the plate path returns live data, and a disambiguation warning that the safety-retrofit reduction is a licence-fee reduction, not insurance. That is substantive behaviour beyond the annotations, though it says nothing about failure modes for unresolvable plates.

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?

Front-loaded with 'Use for...' and organised as capability then mode-by-mode selection, so it reads as a decision aid rather than prose. It is dense and duplicates itself in Hebrew, which costs a little, but every clause carries distinct information.

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?

An output schema exists, so return-shape explanation is unnecessary, and the description instead supplies the domain context an agent cannot get elsewhere: the table dimensions (7 price groups x 4 age tiers), the applicable period, and the add-on/reduction rules. Nothing needed to call this 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, but the description adds meaning the schema does not: which parameters produce which query mode (plate = live exact fee, make+model+year = trim-level, none = full table) and that year is optional. This routing semantics is genuinely useful beyond the field-level 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?

States a specific verb-and-resource ('explain the Israeli annual car licence fee') and immediately bounds scope: private cars up to 3.5 t, with the official table, price-group mechanics, the broadcasting add-on and the safety-retrofit reduction. It is clearly distinguishable from siblings like explain_chova_price or theft_by_model.

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?

Explicitly enumerates the three invocation modes and their selecting conditions: 'With a plate: the exact fee', 'With make + model (+ year): per trim', 'With no arguments: the table.' An agent knows exactly which argument combination to supply without opening the schema.

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