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

No annotations are provided, so the description carries the full behavioral burden. 'Without buying' does signal a non-mutating read, which is helpful, but the description says nothing about the api_key requirement, authentication, rate limits, or the currency/format the price is returned in.

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?

A single tight sentence with the scope constraint front-loaded and no filler. It is efficient, though one more clause on identifier format would have earned its place.

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-value explanation is not required. Still, for a tool needing an API key plus service/country identifiers drawn from sibling listing tools, the description leaves the agent without prerequisite or identifier-format guidance.

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 3 parameters. The description names the two required inputs (service, country) but adds no format or identifier syntax, and the api_key parameter is entirely unexplained in both schema and description.

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 (Get) and resource (retail price) qualified by scope (for a service and country). The phrase 'without buying' implicitly separates it from the buy_number sibling, though it doesn't name that sibling directly.

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 trailing 'without buying' implies this is the pre-purchase price-check step versus buy_number, which is useful implied routing. However, there is no explicit when-to-use statement, no prerequisite callouts (e.g., resolve service/country first via list_services/list_countries), and no exclusions.

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