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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is fully covered. The description adds the endpoint path and the returned field set, which is useful context, but says nothing about pagination behavior, rate limits, or result envelope beyond what the schema's page/per_page descriptions 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, front-loaded with what the tool lists, then the date-window hint, then the API path. Every sentence carries information and none is filler.

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 compensates well by enumerating the returned fields (name, start/end, status, category, location, description, sign-up options, sites). It does not explain pagination flow itself, though the schema's page/per_page descriptions cover that, so the gap is minor.

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 90%, so nearly every parameter is already documented in the schema. The description restates the date-window parameters and their YYYY-MM-DD format, which the schema already provides, adding no new semantic detail. 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?

The description states a specific verb and resource ('List calendar events') and enumerates the fields returned, plus the underlying API endpoint (GET /calendar/events). It is clearly distinct from the singular get_event and from list_event_categories, though it never names a sibling explicitly to reinforce that distinction.

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 gives usage guidance for a parameter ('Use starts_after/starts_before for a date window') but no guidance on when to choose this tool over alternatives such as get_event or list_event_categories. Usage is implied by naming, not stated.

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