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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds real context beyond them: the result source (published WonderKit city guide picks plus page URL) and the scope limitation that only single activities, not multi-day plans or private trips, are visible.

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 tight sentences, front-loaded with the trigger condition, then the return shape, then the exclusions. Every sentence carries distinct information with no repetition of the schema or annotations.

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?

An output schema exists so return values need not be detailed, yet the description still summarizes the return (published picks plus page URL). Combined with annotations covering safety and the schema covering all three parameters, an agent has everything needed to select and call this tool correctly.

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 baseline is 3. The description goes beyond the schema by mapping natural-language phrasing onto the parameters: 'weekend ideas, events, food' illustrate query terms and 'kid-friendly, date-night, or group activities' correspond to the audience enum values families/couples/friends, which helps map a user request to the right field.

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 gives a specific verb and resource ('find activities in one city') and immediately scopes it: published picks from the WonderKit city guide with a page URL. It explicitly rules out adjacent capabilities ('returns single activities, not multi-day plans') and distinguishes itself from trip/itinerary siblings.

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 states a clear trigger ('when someone asks what to do in one city: weekend ideas, events, food, or kid-friendly, date-night, or group activities') and two boundaries (no multi-day plans, cannot see anyone's own trips). It stops short of naming the sibling to use instead (e.g. search_itineraries for multi-day plans), so it is strong but not fully explicit about alternatives.

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