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

The description adds real behavioral context beyond the readOnlyHint annotation: responses are cached by Breeze and may lag up to 15 minutes, which materially affects how an agent should treat freshness. It also clarifies that `id` is the instance id (not the series), a subtle but important behavioral nuance. It doesn't state pagination/ordering behavior, so not a 5.

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?

Three dense sentences, zero filler, all front-loaded: purpose and scope first, then the critical id semantics, then the caching caveat and API path. Every sentence earns its place.

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?

With no output schema, the description carries the return-value burden and does describe the key row fields (`id` vs `event_id`). The 15-minute cache lag covers the freshness concern. Some row fields and result ordering remain unspecified, but nothing critical to correct invocation is missing.

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 already documents start/end format, limit bounds, and category_id sourcing. The description restates the date-range and single-calendar semantics but adds no format or default detail beyond the schema, which is the expected baseline.

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?

States a specific verb+resource ('List event instances') and immediately scopes it by date range, default window, and optional calendar. It also disambiguates the instance-vs-series distinction that separates this tool from breeze_get_event and the attendance/volunteer tools, so an agent can tell it apart from siblings without opening either schema.

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?

Gives a clear default behavior (current month) and the optional calendar filter, and hints at the downstream workflow by noting the id feeds attendance, volunteer and get_event tools. It stops short of explicit when-to-use/when-not guidance against a sibling like breeze_get_event, so it lands at 4 rather than 5.

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