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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, and the description adds genuinely new behavioral context: returns official indicative 'from' prices in EUR exactly as on the website, plus an explanation of how pricing works, plus the caveat that the final price is always confirmed by phone before work starts. That caveat is material for how an agent should present the numbers to a user.

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 trigger condition is front-loaded in the first clause, and the whole thing is one tight paragraph with no filler. The parenthetical service list is slightly long and trails off with an ellipsis, but it earns its place by helping match varied user phrasings.

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 annotations covering safety, a full output schema covering return values, and 100% schema coverage on both parameters, the description only needed to supply trigger context and the pricing caveat — both of which it does. Nothing an agent needs to invoke and present results 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 both the service filter and the language enum are already fully documented in the schema. The description only restates the optional service filter and never mentions the language parameter, so it adds no meaning beyond structured data. Baseline 3 applies.

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 states a concrete verb and resource ('get prices' for drain unblocking, toilet, CCTV camera, boiler installation, etc.) and anchors it to a real source URL (kanalvarna.com/ceni/). An agent can immediately tell this is the pricing lookup, distinct from siblings like list_services or find_service.

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 ('Call this when the user asks how much something costs') and enumerates representative query topics that select this tool. It also explains the optional filtering behavior. It does not, however, name alternative siblings or state when to prefer find_service/list_services instead, so it stops short of full routing guidance.

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