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

readOnlyHint=true already establishes this is a safe read. The description adds the Nylas v3 route and the note that calendar_id is sent as a query param, confirming a plain GET semantically, but says nothing about pagination behavior, default limits, or result ordering. Marginal added value over the annotation.

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 short, front-loaded sentences with no filler; the core action leads and the implementation note follows. The endpoint sentence is slightly marginal but very brief.

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 7-parameter list tool with no output schema, the description does not explain the return shape or pagination flow (page_token consuming next_cursor), leaving the agent to infer behavior. It is adequate but leaves real gaps around paging and time-range filtering.

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 all seven parameters (start, end, limit, page_token, show_cancelled, grant_id, calendar_id) are already documented in the schema. The description only restates the calendar_id requirement, adding no format or interaction detail beyond the schema. Baseline 3 is appropriate.

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+resource ('List calendar events'), which is clearly distinct from the singular-read sibling nylas_get_event and the write sibling nylas_create_event. It doesn't explicitly name an alternative, but the list/get distinction is unambiguous from the name and description.

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 notes that calendar_id is required, which is a prerequisite, but gives no guidance on when to use this tool versus nylas_get_event, nylas_list_calendars, or how it relates to filtering by time range. No when-not or alternative routing is provided.

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