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

Annotations already declare readOnlyHint=true, so the safety profile is carried by structured data. The description adds useful context about the services pseudo-calendar and the date-bounded scope, but says nothing about paging behavior, result caps, or auth requirements despite page/page_size existing. Adequate, not rich.

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?

A single sentence front-loads the core action and date scope, with the calendar option and services tip attached; the endpoint reference is short metadata. No filler or redundant restatement of the parameter list.

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 list tool with full schema coverage and no output schema, the description covers the essential calling contract. It could still note paging defaults or how to obtain calendar ids (likely via list_calendars), which would make it self-sufficient for an agent planning a multi-step call.

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%, so the schema already documents date format, paging bounds, and the fields/calendar params. The description only reinforces the calendar filtering idea and the calendar-id alternative, which the schema already states. Baseline 3 is correct when the schema does the heavy lifting.

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 ("List calendar events") plus scope ("between two dates, optionally for specific calendars"). This clearly separates it from elvanto_create_calendar_event and elvanto_list_calendars without needing to open either schema, and the Elvanto endpoint reference pins the underlying API call.

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?

The description gives real usage context: a required date range and the option to narrow by calendar, including the non-obvious trick of passing "services" as a calendar. It stops short of naming when NOT to use it or pointing to a sibling (e.g. list_calendars to discover calendar ids), so it is clear context without explicit exclusions.

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