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

readOnlyHint=true already establishes the safe-read profile, and the description adds real context on top: what fields come back (id, name, color, iCal feed) and that the id is a foreign key for other tools. It does not discuss result size or ordering, but for a small enumeration this is good.

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?

Two tight sentences, front-loaded with the resource and immediately followed by the high-value cross-tool id note. The trailing raw endpoint string (Breeze: GET /api/events/calendars/list) is mildly redundant for an agent but does not bloat the definition.

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?

There is no output schema, so describing the returned fields falls to the description, and it does so. Combined with the annotations and the cross-tool key explanation, an agent has everything needed to call and use this 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 tool takes zero parameters, so the baseline is 4 and there is nothing for the description to disambiguate. No misuse risk from parameters.

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 (list) and resource (church event calendars) and even enumerates the returned fields. It is clearly distinguishable from siblings like breeze_list_events and breeze_list_tags.

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 explains that the returned id is the category_id consumed by breeze_list_events and breeze_add_event, which effectively tells the agent when this call is a prerequisite. It gives no explicit exclusions or 'do not use when' guidance, so it stops short of a 5.

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