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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuine value beyond that: it names the answering system ('the production engine'), discloses that failure returns 'reasons', and lists hard limits (no filing, no payment, no ELSTER certificate/PIN accepted), which prevents the agent from misusing it as a credentialed or mutating endpoint.

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 the core question before the behavioral limits. It is dense but each clause earns its place; the products/prices clause is the only mildly loose element.

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 strong annotations covering safety, a fully documented schema and no output schema, the description is nearly complete. It even notes that reasons accompany a negative answer, so an agent knows what to expect on rejection; only explicit sibling routing 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?

Schema description coverage is 100%, including detailed per-parameter notes (stichtag omission forces eligible=false, enum semantics for groesse and rechtsform), so the schema carries the burden. The description only names the three inputs (legal form, size class, fiscal year) without adding syntax or format meaning beyond the schema, so baseline 3 applies.

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 states a specific verb and resource: it answers whether a company 'can be served' based on legal form, size class and fiscal year. However, the rider that it 'answers questions about eBilanz Fabrik's products, prices' overlaps with the sibling tools ebf_get_pricing and ebf_get_products, muddying rather than sharpening the 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?

There is no explicit 'use this instead of X' routing, but the negative scoping ('prepares nothing, never files, never takes payment, never accepts an ELSTER certificate') implicitly tells the agent this is a pure inquiry tool, not a filing or payment tool. Usage context is implied rather than stated.

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