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

No annotations are provided, so the description carries the full burden. 'Get' implies a safe read and the field list previews the payload, and it uniquely discloses a cost model ('Flat 5 points per successful run'). It omits auth, rate-limit and error/not-found behavior, so the safety profile is only partially covered.

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?

One front-loaded sentence covering the action, key and payload, followed by a short cost note. Efficient and easy to scan, with no filler.

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?

No output schema exists, and the description does compensate by enumerating returned fields (price, description, location, attributes, images, seller). However, with no annotations and a single param it leaves auth, failure modes and pagination-style concerns unaddressed, so it is adequate rather than complete.

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 100% and there is only one parameter, so the baseline is already satisfied by the schema's 'Ad ID or URL. e.g. 3517031976'. The description adds marginal meaning ('by id or URL') but no format detail beyond the schema; with a single well-documented param the minimum-viable baseline holds.

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 ('Get one Kleinanzeigen ad') plus the retrieval key (id or URL) and the fields returned. The 'one' vs the sibling 'listings_search'/'listings_similar' is implied rather than named, so it stops short of explicit sibling differentiation.

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?

Usage is only implied: fetching a single ad when you have its id or URL. It never names the alternatives (listings_search, listings_similar) or states when to prefer this over them, leaving routing to inference.

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