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

With no annotations, the description carries the full burden. It usefully discloses the default window (7 days from today) and the timezone (Taiwan time), but says nothing about read-only nature, return format, or pagination behavior for a listing tool.

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?

A single compact sentence that front-loads the scope and appends the default window and timezone. No wasted text, though brevity comes at the cost of usage guidance.

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 2-parameter tool with no output schema and no annotations, the description covers the temporal scope and timezone but leaves 'important dates' undefined and does not distinguish this tool from the six sibling alternatives.

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 50%: 'date' is documented as YYYY-MM-DD while 'days' has no schema description. The description compensates by explaining that the range starts from a given day and defaults to 7 days, which the schema does not encode as a default.

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 resource and scope: in-progress events and important dates within a day-range starting from a given date. It is clear enough for an agent to act, but it offers no differentiation from siblings such as sports_calendar or list_sports_events.

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?

There is no statement of when to use this tool versus alternatives like sports_calendar, event_countdown, or list_sports_events. The only guidance is the built-in default window, which describes behavior rather than selection criteria.

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