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

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true, so the agent knows it's a safe read operation. The description adds a scoping detail (events that are 'scheduled and published') and mentions filter categories, but doesn't disclose pagination behavior or return format. This is consistent with the calibration example where extra context earns a 3.

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, front-loaded sentence that immediately states the core purpose and then lists the optional filter categories. No wasted words or redundant details—it is efficiently concise.

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 listing tool with 8 optional parameters and no output schema, the description covers the essential behavior and filter options. Annotations provide safety context, and the schema fully documents parameters. It doesn't explicitly mention that it returns a list of events, but the verb 'List' implies that. Given the tool's simplicity and rich annotations, this is sufficiently complete.

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 description coverage is 100%, so the schema fully documents all 8 parameters. The description merely summarizes them ('date-range, status, platform, and pagination filters') without adding new meaning or clarifications beyond what the schema already provides. Thus, 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 clearly states the action ('List') and the resource ('calendar events') with specific scope ('scheduled and published'), which distinguishes it from mutation tools like update_calendar_event. However, it doesn't explicitly differentiate from sibling list tools like get_scheduled_posts or list_recurring_series, so it falls short of a 5.

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 provides no explicit guidance on when to use this tool versus alternatives. It mentions filters but doesn't state when this is the right choice over get_scheduled_posts, get_calendar_gaps, or list_recurring_series. There are no exclusions or alternative tool mentions.

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