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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive, so the safety profile is partially covered. The description adds behavioral context beyond the annotations, notably the anti-spam constraint that agents must not initiate outbound contact and that responses are served in de/en. It does not describe any auth, rate, or freshness behavior, keeping it from a 5.

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?

The single block is reasonably front-loaded with the resource before the constraints, but it is cluttered: an actual phone number literal is embedded in the description, and German prose mixes with English terms and a language-tag parenthetical. Some content (the specific number) does not help the agent decide or invoke, mildly diluting conciseness.

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?

There is no output schema, but the description enumerates the returned contact fields (mobile, landline, WhatsApp link, email) and supported languages, so the agent knows the shape of the result. Combined with the routing constraint, it is nearly complete for a zero-parameter read tool, with only minor gaps such as whether the contact data is static or fetched.

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 per the rubric the baseline is 4. Schema coverage is 100% and there is nothing for the description to clarify; no penalty or bonus 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?

States a specific resource (contact data from Impressum/Kontakt) and enumerates the returned channels (Mobil, Festnetz, WhatsApp-Link, E-Mail), so the agent knows what comes back without opening the schema. It does not explicitly differentiate itself from the sibling tools (get_flyer, get_listing, search_listings), so it falls short of a 5.

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?

Gives explicit when-to-use and when-not: 'NUR dem Menschen zum Tippen zeigen nach klarem Kontaktwunsch' plus 'Agents starten KEINE Calls, WhatsApp- oder E-Mail-Nachrichten (Anti-Spam).' This tells the agent both the trigger condition and the prohibited follow-up action, which is unusually complete routing guidance.

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