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

Annotations already flag openWorldHint=true, so the description adds real value by disclosing the filtering rule (current public events only, active upcoming dates) and the empty-result semantics. It does not contradict the annotations, though it says nothing about paging behavior or what fields come back, leaving some behavioral ground uncovered.

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?

Four short sentences, each doing distinct work: trigger, scope, empty-result caveat, and sibling routing. The most decision-relevant information (when to use, what is excluded) is front-loaded with no filler.

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 shape need not be explained, and annotations cover the safety profile. What's missing is any acknowledgment of the geo/proximity parameters on a tool with a nested object input, which is the one gap an agent could stumble on.

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?

The description mentions no parameters at all; all meaning comes from the schema, which covers only about half the inputs (term, maxDistanceKm, origin lat/lng) and leaves 'limit' undocumented. Most notably the description never signals that proximity search via origin/maxDistanceKm is supported, a capability an agent would have to infer from the nested 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?

States a specific verb and resource ('Search ... current public WellFred events with active upcoming dates') and narrows scope to Costa Rica and upcoming events/retreats. It explicitly contrasts with the 'services' sibling, so an agent can route without opening another schema.

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?

'Use when the customer specifically wants upcoming events or retreats' gives the trigger, and 'Use services for ongoing offerings' names the alternative and the condition that selects it. The caveat that an empty result doesn't mean a provider never offered events tells the agent how to interpret a null response rather than concluding no inventory exists.

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