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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds genuinely new behavioral context: it enumerates the returned fields and currency/unit conventions and implies the result set is complete ('every'), i.e. no pagination. It does not discuss error cases or ordering, so it stops short of 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?

A single front-loaded sentence with no filler; the verb and resource come first and the field enumeration is the only elaboration, which is justified because no output schema exists.

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 one-parameter, read-only listing tool with no output schema, the description supplies the field inventory that the schema omits and documents both language options, which is close to sufficient. It omits any statement about result size or pagination behavior beyond the implicit 'every'.

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 description coverage is 100% and the single 'lang' parameter is fully documented in the schema, so the baseline of 3 applies. The phrase 'in English or German' restates the enum values and only marginally extends meaning beyond the schema's 'Language of names and descriptions'.

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 and resource ('Lists every seelig.ai service') plus the exact fields returned (id, price in CHF, duration in weeks, deliverable, page URL). The scope word 'every' and the sibling set (get_free_slots, request_booking) make it obvious this is the catalog tool, not a booking tool.

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?

There is no explicit 'use this when…' or 'use X instead' guidance. Usage is only implied: an agent can infer this is the tool for discovering the service catalog prior to booking. Neither get_free_slots nor request_booking is referenced, so the routing must be inferred from the names.

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