list_series_instances

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

With no annotations provided, the description carries the full burden. It discloses a key behavior: 'Accepts any event ID from the series (resolved to master automatically).' However, it does not mention return format, error cases, or side effects (though listing implies read-only). This is partial transparency.

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 concise, using two sentences that front-load the primary action and then add a key usage detail. No wasted words.

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 listing tool with no output schema and no annotations, the description is adequate but leaves gaps. It explains the core purpose and the eventId resolution but does not describe what the response contains (e.g., list structure, fields) or edge cases like empty results. More detail would improve completeness.

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 provides 100% description coverage for all four parameters. The tool description adds no additional parameter meaning beyond what the schema already states (e.g., eventId resolution). Baseline of 3 is appropriate because the schema does the heavy lifting.

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's function: 'List all occurrences of a recurring series within a date range.' It uses a specific verb ('List'), specific resource ('occurrences of a recurring series'), and the date-range scope distinguishes it from sibling tools like get_series_master or get_calendar_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?

The description provides clear context: use this tool to list occurrences of a recurring series within a date range, and it accepts any event ID from the series. While it doesn't explicitly name alternatives or exclusions, the purpose is clear enough to infer when to use it versus other calendar tools.

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