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

Annotations already declare readOnly/openWorld/idempotent/non-destructive, so the safety profile is covered. The description adds genuinely new behavioral context: WAB courses may use external partner booking calendars, unknown/stale availability is explicitly labelled, and the tool does not reserve or pay. That goes beyond the 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?

Three tightly packed sentences, front-loaded with purpose and result contents, then routing, then behavior caveats. Slightly dense but every clause earns its place.

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 enumerates the return contents (language, prices, all sessions, availability, booking links). Combined with annotations, an agent has enough to invoke it correctly, though it doesn't mention pagination or the limit default.

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 67%, and the schema documents city, language (response vs teaching distinction), from_date, and teaching_language. The description restates teaching language and touches course types but adds no syntax or format detail for limit or course_type beyond the enum values. Baseline 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 verb ('Find') plus the exact resource and scope ('upcoming VKU, first aid/Nothelfer or WAB courses by town'), and enumerates what the result carries (language, prices, sessions, availability, booking links). It also differentiates from the sibling by pointing to list_course_locations for coverage, so an agent can distinguish it without opening any schema.

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?

Explicitly routes coverage/lookups to list_course_locations and states the hard boundary 'Does not reserve or pay'. It gives clear context for when this search applies, though it doesn't spell out the selection condition against search_driving_lessons or get_lesson_availability.

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