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

Goes well beyond the readOnly/destructive annotations by disclosing the progressive relaxation order (drops time of day, then widens dates; never drops categories, price or «free») and that the response reports what was relaxed. Also says each pick carries a short `why` and event 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?

Front-loads the signature feature and consumes no filler, but the middle sentence packs filtering, relaxation order, and follow-up routing into one long run-on. Dense and useful, though slightly harder to scan than a segmented version would be.

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 15-parameter tool with nested `near` and an output schema, the description covers selection purpose, filter behavior, degradation policy, and conversation-follow-up mechanics. Return format is covered by the output schema, so nothing an agent needs to invoke it correctly 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 schema already documents all 15 parameters, establishing a baseline of 3. The description adds genuinely new semantics for two of them — that `exclude` should receive `exclude_next` from the prior result and that `count` caps at 3 different picks — which lifts it above baseline.

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 — 'pick ONE random worthwhile event (or up to 3)' matching filters — and immediately lists the user utterances it serves. This is clearly distinguishable from list/search/get siblings by the random-pick semantics.

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?

Maps concrete triggers («удиви меня», «куда-нибудь сходить», «не могу выбрать») to the tool, and routes the two follow-up cases explicitly: `like_event` for 'something else at the same day/time' and `exclude` with `exclude_next` for 'ещё раз / другое'. The condition selecting each alternative is spelled out.

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