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

Annotations already establish read-only and idempotent behavior, so the description's job is to add operational context – and it does: geographic scope (Lithuania), a coverage caveat ('where the operator publishes them'), and a breakdown of the fee categories returned. It stops short of saying how fresh the prices are or what happens when an operator has no published tariffs.

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?

Two sentences, front-loaded with scope and price components, followed by accepted input forms. The fee enumeration is dense but each clause conveys a distinct returned field; nothing is padding.

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 carries the return-value burden and does so concretely (dimensions, currency, VAT inclusion, fee types, subscription plans). Remaining minor gaps are price freshness and behavior on an unknown operator.

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 accepted forms (brand, legal name, slug) with examples, so the description's repetition of 'Ignitis ON', 'Eldrive', 'ignitis-on' adds little beyond the schema. Baseline 3 applies; no match-resolution or fallback behavior is described.

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 resource (current EV charging network tariffs for one operator in Lithuania) and enumerates what the record contains: min/typical EUR/kWh incl. VAT split by AC, DC (<150 kW) and HPC (≥150 kW), plus per-minute, parking, session fees and subscription plans. It does not explicitly contrast itself with siblings like charging_cost or cheapest_charging, but the operator-level tariff-card framing makes it distinguishable.

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?

Usage is implied rather than stated: you call it when you want the published price card of a named network. There is no explicit when-not guidance and no routing to charging_cost or cheapest_charging, which an agent comparing cost tools would benefit from.

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