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

Annotations already declare readOnly/openWorld/non-destructive, so the safety profile is covered. The description adds genuinely useful behavior beyond that: lost events only appear when status=lost (with the lost reason) and it requires a Cotlet API key with app access. These are non-obvious filtering/auth traits that annotations do not convey.

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 sentences with no dead weight, and it front-loads what the tool returns before describing filters. The opening ('like Reports, Events:') is slightly awkward, but overall it is tight and well-oriented.

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?

There is no output schema, so the description correctly covers the return shape (one row per event with the named columns). Combined with the auth requirement and filter semantics, an agent has enough to call it correctly; pagination via cursor is only in the schema, leaving a small gap.

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 meaning on top: it explains that the filters mirror a custom view and clarifies the semantics of created vs event dates and the special lost-status behavior, going slightly beyond the raw 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 gives a concrete verb+resource ('Returns the rows of the Events report, one line per event') and enumerates the columns (status, owner, dates, sales breakdown), which distinguishes it from a plain event list. It stops short of naming the sibling list_events tool it should be preferred over, so it misses the explicit sibling-routing that a 5 requires.

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 concrete when-to-use guidance ('Use created dates to count new leads in a week and the status filter to count confirmed events') which tells the agent how to drive the filters for real questions. It does not state when to prefer this over list_events or get_event, so it is clear context without exclusions.

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