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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so safety and idempotency are fully covered structurally. The description adds only the dispatch pattern and the upstream-ID dependency; it says nothing about pagination behavior, result limits, or what an interest record represents beyond what annotations already imply.

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 short sentences with the resource and dispatch mechanism front-loaded and zero filler. The clipped "Dispatch via action" is efficient but slightly under-explained, trading a little clarity for brevity.

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 no explanation. However, for a polymorphic oneOf tool with two distinct actions, the description never enumerates the actions or distinguishes their behaviors, so the agent must open the schema to understand what the tool can actually do.

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 baseline is 3. The description restates the event_id semantics that the schema already documents verbatim ("Event UUID returned by search_events") and is silent on the meaningful parameters — action values, page, and query — leaving the schema to carry all of it.

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 ("Read interests for the provided event") and names the dispatch mechanism (action), which cleanly separates it from create_interest, update_interest, and delete_interest. It does not, however, differentiate the sub-operations (list vs get) that the tool actually performs.

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?

Gives one concrete prerequisite: event_id must be the UUID returned by search_events, which usefully chains it to that sibling. But it never says when to use 'list' versus 'get', nor what to do when only a name is known (no guidance on the query parameter), so usage is only implied by the schema's oneOf.

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