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

Annotations already declare a safe, idempotent, non-open-world read, so the description focuses on content behavior: it returns coming nights with date, DJ, DJ origin, short introduction, and special nights, and explicitly states that nights without a DJ say so. That edge-case disclosure is genuinely useful. It adds little about pagination or how many nights are returned, which keeps it below 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?

Dense but purposeful: venue and schedule context first, then return contents, then example user intents. It is one long sentence chain, so the usage examples are slightly buried at the end, but no sentence is 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?

For a read-only single-parameter lookup with an output schema and full annotation coverage, the description supplies everything needed: what it returns, what happens when data is missing, when the club operates, and which user questions it answers.

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?

There is a single optional enum parameter whose schema description already covers the allowed values (de, nl, en) and the default. The description never mentions the language parameter, so it adds no meaning beyond the schema; with 100% coverage the baseline of 3 is appropriate.

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 and scope: the club line-up for Mondschein Club's Electronic Friday, with venue context. It clearly distinguishes itself from the generic list_events sibling by naming the club, the weekly cadence, and the exact fields returned.

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 example intents ('what is on at the club', 'who plays on Friday', nightlife questions) and notes practical conditions: no reservation, usually free entry, winter Fridays 21:30–02:00. It does not explicitly contrast itself with list_events or list_offers, so the alternative-selection guidance 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.