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

Beyond the readOnly/no-side-effects annotations, it discloses the source of truth (public price list only), the non-binding nature of the output, the clarification behavior when needs are ambiguous, and the no-price outcome for out-of-scope requests. These are real behavioral traits an agent cannot infer from the annotations.

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 what the tool does and what it returns, then behavior, then caveats. Dense but nearly every clause carries information; the parenthetical price breakdown and the VAT note are slightly compressed into one long sentence but still readable.

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?

There is no output schema, and the description compensates by enumerating the returned fields (one-time, yearly and first-year prices ex 21% VAT, what is included, when they pay). Combined with the scope and ambiguity rules, an agent has everything needed to call it and interpret the result.

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 already 100%, but the description adds meaning on top: 'need' accepts plain Dutch or English, and for 'features' it states the decision rule that the most capable feature decides the product. It adds little for 'locale' beyond what the schema says, which keeps it from a 5.

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: maps a need to exactly one product and returns its prices, inclusions and payment timing. This is clearly distinct from the siblings (list_products, list_work, request_contact), which do none of these things.

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?

Gives concrete usage context: describe the need in plain Dutch or English and/or pass features, and it will ask questions if the need is unclear. It also defines the out-of-scope case (outside the four products, e.g. an App Store app returns no price). It does not explicitly route the agent away from list_products when browsing the catalog, but the conditions for calling it are clear.

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