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

Annotations already declare read-only, idempotent, non-destructive, closed-world behavior, so the bar is lower. The description still adds real operational context the annotations lack: a hard cap of 50 results, sort order by start time, that entries are pre-verified, and that each item should surface a mutify_url or ticket_url.

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?

One dense sentence plus a return-shape clause, front-loaded with the core promise (what's on today in Berlin) before the constraints and the portal link. There is little waste, though the parenthetical portal inventory (Karte, Wetter, Klima, Bezirke) is arguably padding.

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 output schema, the description usefully covers the return shape (max 50, sorted, per-item urls, portal link). But it leaves 'kategorie' completely unspecified and offers no guidance on sibling tools, which is a meaningful gap for a filter-bearing discovery tool.

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?

Only two parameters and schema coverage is 50%. The description merely restates that 'datum' can substitute for today, which the schema already documents, and 'kategorie' — an undocumented free-form string with no enum — gets no explanation of accepted values at all.

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 concrete verb+resource in German: it returns 'gepruefte Veranstaltungen in Berlin' for today or a given date, capped at 50 and sorted by start time. That is specific enough to distinguish it from the sibling list-oriented tools, though it never names those siblings explicitly.

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 a clear trigger ('Was ist heute (oder an datum)') but no exclusions or alternatives — nothing says when to use termine_suchen or staedte instead of this Berlin-only shortcut, leaving the routing to inference.

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