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

With no annotations, the description must disclose behavioral traits. 'Get upcoming' implies a read-only operation but does not specify the time window, calendar scope, or output format, leaving behavioral ambiguity for a tool with no safety annotations.

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 a single sentence with no unnecessary words, efficiently conveying the core function. It is concise and front-loaded.

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?

The description is sparse: it does not define 'upcoming' (e.g., how many days ahead), does not mention whether it covers all calendars, and lacks an output schema. For a 0-parameter tool, the description provides minimal context, making it less complete for reliable invocation.

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?

Since the tool accepts no parameters (schema coverage 100%), there are no parameter semantics to clarify. The baseline score of 4 is appropriate as the description has nothing to add.

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 the tool retrieves upcoming Google Calendar events, using a specific verb ('Get') and resource ('Google Calendar events'). It distinguishes itself from sibling tools like create_calendar_event and check_freebusy by scoping to retrieving upcoming events, though it doesn't explicitly contrast with search_calendar.

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?

No guidance is provided on when to use this tool versus alternatives like search_calendar or weekly_preview. The description gives no context about appropriate use cases, making it ambiguous for an agent selecting among calendar-related tools.

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