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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds that results are cursor-paged and ordered newest-first by default, but the cursor mechanics and the large-page character cutoff are already documented in the schema, leaving little genuinely new behavioral disclosure beyond confirming this is a read operation.

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, zero filler. The core purpose is front-loaded, pagination follows, and the alternative-tool pointer is last — the correct order of importance.

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 names the event kinds a caller will receive and notes cursor paging, which is what an agent needs to plan a loop. It stops short of describing the response envelope (next_cursor field, per-event fields), but the schema's cursor text partially compensates.

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 100% and every parameter (campaign_id, limit, order, cursor, event_date_from, event_date_to) is documented with format, bounds, and inclusivity semantics. The description only restates date-range filtering and default ordering, so baseline 3 applies.

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 resource (recipient events of one campaign), enumerates the event types returned (delivered, opened, clicked, bounced, unsubscribed), and specifies default ordering and date-range scoping. It also explicitly contrasts itself with laposta_get_report, which handles totals, so an agent can separate it from the nearest sibling without inspecting schemas.

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?

Explicitly routes the agent: 'For totals use laposta_get_report.' That is a clear when-to-use-this-instead rule. It does not address related siblings such as laposta_get_campaign, laposta_get_campaign_content, or laposta_get_member_history, so the routing is incomplete but not ambiguous.

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