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

Annotations already cover readOnly, idempotent, non-destructive and closed-world, so the bar is lower; the description still adds real value by stating the data is 'as the server itself reports' and, importantly, that it never accepts an ELSTER certificate or PIN, which is an auth/secret-handling disclosure not present in the annotations. The negative list (prepares nothing, never files, never takes payment) further constrains behavior.

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, with the core answer front-loaded. The trailing negative enumeration is somewhat long and slightly redundant with the read-only annotations, but each clause does bound behavior rather than pad.

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 no parameters, no nested objects and no output schema, an agent has enough to invoke the tool correctly and knows the subject matter of the response (products, prices, scope). Only the return shape/pagination is unaddressed, which is a minor gap for a zero-arg read.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate; the baseline of 4 applies. The description correctly implies a parameterless catalog query rather than hinting at hidden filters.

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 question ('which eBilanz Fabrik products can be bought right now'), so an agent knows exactly what the call returns. It does not name or contrast the sibling tools ebf_get_pricing and ebf_check_eligibility, and its second sentence ('products, prices and whether a company's legal form, size class and financial year are in scope') arguably overlaps with both of them, leaving the boundary a little blurry.

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 implied by the framing question ('can be bought right now'), and the exclusions are about actions rather than alternatives. There is no explicit guidance on when to prefer this over ebf_get_pricing or ebf_check_eligibility, which is exactly the confusion the overlapping subject matter invites.

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