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 the useful behavioral detail of result ordering (largest event count first) and that only cities with a live board are returned. It does not mention the default/max result count behavior, but that is minor against the annotation coverage.

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 sentences, zero filler, with the what/ordering stated first and the routing/usage guidance second. 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?

An output schema exists, so return-value structure need not be explained. Given a read-only, annotation-covered list tool with three simple params, the description supplies everything an agent needs to select and 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 description coverage is 67%, and the description reinforces the two documented filters (partial name match, country) but adds no new syntax or format detail beyond the schema. The 'limit' parameter is undocumented in both the description and the schema, so the description does not compensate for the coverage gap.

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 states a specific verb and resource ('List the cities that currently have a live events board') plus scope and ordering ('biggest first'), so the agent knows exactly what comes back. It also differentiates itself from the sibling search_events by framing itself as a coverage/name-resolution lookup rather than an event search.

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 explicit when-to-use guidance ('Use it to check coverage or to find the exact city name before calling search_events'), naming the sibling it feeds into. The filtering options (part of a name, country) are also tied to concrete intent.

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