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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds real behavioral context beyond that: the response carries dated sources and uncertainty, and may contain disclosed external attraction-admission referrals, which explains the openWorldHint. It still doesn't say anything about error behavior or shape/size of the result.

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?

Two dense sentences, front-loaded with the retrieval contract, followed by what the payload contains and what it does not. 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 covers the return contents (sources, uncertainty, referrals) and negative capability scope. However, for a tool with four parameters including a nested required-by-schema-optional object, the total silence on `party` and `filters` leaves the agent unable to use those parameters 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 description coverage is 0%, so the description carries the full burden and largely fails it. Only the `ids` parameter is hinted at ("ID returned by search"); `city`, `party` (adults, child_ages, ticket_category) and `filters` (indoor, stroller, max_admission_usd, all_children_suitable) are undocumented in both schema and description, and the nested `party` object is non-obvious.

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?

Specific verb and resource ("Get one activity") with the exact identifier source ("an ID returned by search"), which implicitly separates it from search_family_activities. It stops short of naming the sibling tools, so it isn't fully differentiated.

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?

The phrase "using an ID returned by search" establishes the prerequisite and the call order clearly. The closing sentence also sets explicit out-of-scope boundaries (no live inventory, reservations, payment, paid digital products), though no alternative tool is named for those cases.

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