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

Adds real behavioral context beyond the readOnly/openWorld annotations: values are read as published with no verification of operator correctness, and it discloses the paid x402 pricing model including that failed calls are free. It stops short of describing pagination, size limits, or failure modes for non-German/non-Impressum pages.

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 what is read and what is returned, with caveats and pricing trailing. Dense but each clause carries information; the pricing parenthetical is slightly long but relevant to cost-aware agents.

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?

For a single-parameter read-only tool with an output schema, the description covers the resource, the returned fields, the accuracy caveat, and the billing model. Nothing an agent needs in order to decide to call or to interpret charges 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?

Only one parameter and schema coverage is 100%, so the schema already documents the url field fully. The description restates the same constraint ('at the page URL you give') without adding format, validation, or redirect-handling detail beyond the schema.

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?

Uses a precise verb ('Reads') with a narrowly defined resource ('the Impressum ... at the page URL you give') and enumerates the exact fields returned (e-mail, phone, postal address, notice text as Markdown). The German-Impressum specificity makes it trivially distinguishable from the generic crawling and news-search siblings.

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 description implies the precondition that the URL must point at an Impressum page, but it names no alternatives and gives no explicit when-not guidance (e.g. versus search_website_content_crawler for general page text). Usage is inferable rather than stated.

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