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

Beyond the readOnlyHint annotation, the description discloses useful behavior: data comes from thousands of calendars, is updated hourly, and includes cancelled and moved events. It does not cover rate limits or return format, but it adds meaningful operational context.

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?

The description is front-loaded with the core purpose and then lists filters and data-source context in one dense but useful sentence. The long theme list is somewhat heavy, but every element helps an agent understand supported queries.

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 read-only search tool with no output schema, the description is largely complete: it explains what is returned, geographic and temporal scope, filters, freshness, and handling of cancelled/moved events. It could still say more about result format or pagination, but an agent has enough to call it 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, but the description adds a meaningful constraint not present in the schema: results are within 25 km of the place. It also reinforces the default weekend behavior and theme examples, though most parameter detail is already in the schema.

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 names a specific resource (activities and events), a clear geographic scope (in and around a Dutch place, within 25 km), and temporal/filter options. It is immediately distinguishable from unrelated siblings such as files, vacatures, or zorgpremies.

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 gives clear context for when the tool applies: finding events this weekend, today, tomorrow, on a date, for children, indoors, or by theme. It does not explicitly state when not to use it or name alternatives, but no direct sibling alternative exists.

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