Event Time Series

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds no behavioral detail beyond the schema: it says nothing about return format, defaults, sparse or zero-filled buckets, timezone behavior, or how the 'open world' event set is handled.

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 only two sentences, front-loads the action, and contains no verbose filler. The second sentence is a somewhat generic use-case statement, but it does not meaningfully hurt clarity.

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?

This is an 8-parameter tool with nested filter objects and no output schema, yet the description gives no hint about the response shape, what 'custom events' means in this product, or default date/bucket behavior. The schema compensates for parameters, but the absent output schema leaves a significant gap that the description does not fill.

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%, and the schema already provides detailed guidance on bucket granularity, filters, dates, and timeZone. The description's 'configurable buckets' merely restates the schema and adds no new parameter meaning.

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 clear verb and resource: 'Get custom event counts as time-series data with configurable buckets.' This distinguishes it from non-timeseries event-count tools like rybbit_get_site_event_count and from overview/performance timeseries, though it does not explicitly name any sibling.

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 phrase 'Useful for analyzing event trends over time' implies a use case, but it does not explain when to prefer this over sibling tools like rybbit_get_overview_timeseries or rybbit_get_metric, nor does it give exclusion criteria.

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