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

The description adds meaningful behavioral details beyond the annotations: the ±31-day default, the 366-day maximum window, and especially the rule that intervals touching only at an endpoint are not conflicts. These are not obvious from the schema and are important for correct interpretation of results.

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?

The description is short, front-loaded with the core purpose, and each sentence covers a distinct piece of information. It is compact and useful, though a few points are also present in the schema descriptions.

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 tool with five optional parameters and rich schema/annotation coverage, the description covers the essential operational context: defaults, limits, proposed-slot usage, calendar filtering, and the conflict-boundary rule. It does not specify exact behavior when the window limit is exceeded, but this is a minor omission.

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 coverage is 100%, so the baseline is 3. The description adds extra value by tying start/end to the 'before create_event' workflow and clarifying that the interval boundary rule applies to overlap, which is not fully stated in the parameter schema.

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 clearly states a specific verb and resource: 'Find overlapping events in the authenticated user calendar.' It also establishes the time-window scope and the proposed-slot use case, which distinguishes it from sibling tools like search_events or get_free_slots.

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 concrete when-to-use context: use the optional start/end to validate a proposed slot before calling create_event, and use calendarId to narrow the search. It does not explicitly name alternatives or exclusion conditions, so it has clear context without full alternative routing.

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