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

Annotations already declare readOnly/openWorld/idempotent/non-destructive, so the safety profile is covered. The description adds real value beyond that: the required from/to constraint, that results are paginated, and that only account-accessible data is returned. It does not mention rate limits or response shape, keeping it below a 5.

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 dense sentences with the core purpose front-loaded, followed by filtering, defaults, and limitations. Every sentence carries information, though the closing 'Limitations' sentence overlaps with schema-documented pagination.

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 14-parameter read tool with no output schema, the description covers the essential filtering and pagination context an agent needs, but it leaves several parameters (auth variants, include_custom_fields, global_company, account_id) unexplained and gives no hint about the returned event shape. Adequate but with clear gaps.

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 64%, so the schema documents many parameters itself. The description usefully clarifies the filter enum's role (USER default, COMPANY for global events) and the id/auto-resolution behavior, but it says nothing about the auth parameters, account_id, global_company, or include_custom_fields, leaving part of the coverage gap unaddressed.

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?

The first sentence gives a specific verb (Lists), resource (time events), source endpoint (/events), and scope (date range). It also distinguishes itself from list_company_events by pointing to that sibling for global account-level events, so an agent can tell the two apart without opening either 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?

It explicitly states the fallback behavior when filter/id are missing (defaults to USER, auto-resolves caller user_id) and names the alternative list_company_events for company-wide events. It does not clarify the boundary against the closer sibling list_filtered_events, so it stops short of full when/when-not guidance.

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