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

Annotations only supply readOnlyHint and openWorldHint, so the description carries the rest and does it well: it discloses the 999-result cap XING reports, that posting time and salary are only present "when XING shows it" (i.e. nullable fields), that some listings are external partner ads, and the exact billing model ($0.002 USDC per successful call via x402, no charge on failure). The one redundancy is re-listing return fields that the output schema already documents.

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?

It is front-loaded correctly, opening with the source, region, and inputs before related tools and price. However, the single sprawling sentence with an eight-item return-field list duplicates the output schema, and the sibling paragraph contains a visibly truncated clause that weakens an otherwise clean structure.

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 an output schema present, return values need not be explained, and the description still covers region, cost, result cap, and field reliability caveats, which is what an agent needs to decide and call. The gaps are minor: no note on rate limits or latency, and no mention of the pagination parameter's role relative to the 999 cap.

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%, including an example for keywords and example cities for location, so the schema already does the heavy lifting and the baseline of 3 applies. The description reinforces which parameter is required versus optional but adds no syntax, matching, or formatting detail beyond the schema, and never mentions the page parameter or its 1-20 bound.

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 names a specific resource and source ("Job listings from XING"), gives the geographic scope (Germany, Austria, Switzerland), the inputs (keyword and optional location), and enumerates what comes back (title, company, location, employment type, salary band, posting time, partner-ad flag, URL). This is enough to distinguish it from the many other job-board siblings without opening the schema.

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 explicitly routes the agent to alternatives, naming jobs_dice for tech roles from Dice and jobs_indeed for Indeed searches, which establishes when this tool is not the right pick. The DACH scope plus the regional implication is a clear context signal. It loses a point because the jobs_dice clause is truncated ("for a keyword and optional;") and the selection criterion for choosing XING is left implicit rather than stated.

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