calendar_query

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

There are no annotations, so the description carries the burden. It discloses the efficient-search behavior, the performance reason, and the automatic cross-calendar scope. It does not explicitly state read-only or describe the result shape, but 'search and filter' plus the schema's note that the response states match counts makes the behavior clear enough.

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 compact and front-loaded with the 'PREFERRED' signal. Every sentence earns its place: one gives the action, one gives the alternative to avoid, and one gives the default-scope behavior. No filler or repetition.

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 query tool with six optional parameters and no output schema, the description plus the rich parameter documentation gives enough to call it correctly. It clearly routes away from list_events, explains the all-calendars default, and the schema covers filter usage. The main omission is an explicit statement of what the returned events look like, but this is not critical for a search tool.

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?

The input schema already documents all six parameters in detail, including examples, defaults, and constraints, so schema coverage is 100%. The top-level description adds cross-calendar context but does not need to repeat parameter semantics; 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 names a specific action ('Search and filter calendar events') and a specific resource, while immediately differentiating itself from list_events. The 'PREFERRED' marker and cross-calendar note make the tool's role unmistakable.

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 explicitly tells the agent to prefer this over list_events to avoid loading thousands of entries. It also gives a concrete rule for calendar_url: omit it to search across all calendars, and the schema reinforces the routing by saying not to call list_calendars first.

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