get_driving_rules

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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the agent knows it is a safe read. The description adds valuable behavioral context beyond that: results are sourced and dated and the attribution must be shown, the tool is not legal advice, and the city parameter behaves differently per topic (narrows lez, adds a per-city caveat for ev, while other topics stay nationwide). No contradictions with annotations.

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 description is long but every sentence earns its place. It front-loads the purpose and topic list, then gives usage rules, exclusions, city behavior, language guidance, and sourcing. It is structured and scannable, though a bit dense. It could be slightly tighter, but it is far from bloated given the tool's complexity.

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?

For a tool with 9 topics, no output schema, and sparse annotations, the description covers everything an agent needs: what it returns, when to use it, when not to, how the city parameter modifies results, the mandatory language setting, and the need to show attribution and note it is not legal advice. Nothing essential 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 coverage is 100%, so the baseline is 3. The description adds extra meaning on top of the schema: for 'city' it explains that it narrows only the 'lez' topic and adds a caveat for 'ev' while other topics are nationwide; for 'language' it stresses that the default is only a fallback and must be set to the user's language, and it explains translation behavior (German terms kept in parentheses). These details go beyond the schema's property descriptions, so a 4 is warranted.

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 opens with a precise statement: returns German road rules a visitor needs, then enumerates the exact topics (low-emission zones, speed limits, winter tyres, etc.). It names the resource (German road rules) and clearly differentiates from siblings by explicitly excluding live traffic and charger lookups, so an agent can tell this apart without reading other schemas.

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 gives explicit use cases ('Use when someone drives through Germany or asks whether they may enter a city') and explicit non-use cases with named alternatives ('Do NOT use for live traffic or closures: check_autobahn_traffic; to FIND a charger: find_charging_station'). It also explains the optional city parameter narrows results and that the language parameter must be set to match the user's language, with a fallback rule. This is fully actionable routing guidance.

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