List events the app doesn't send yet

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

Annotations already declare readOnlyHint=true, so the description does not need to state safety. It adds useful domain context about what these events represent, but it does not disclose any additional behavior such as sorting, pagination, or output format. This is adequate for a simple list tool but not rich beyond the annotations.

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 three short sentences, front-loaded with the core purpose, followed by a meaningful elaboration and a clear usage directive. Every sentence earns its place with no redundancy or fluff.

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 zero-parameter, read-only list tool with no output schema, the description is sufficient: it defines what is listed, why it matters, and how to start using it. It could explicitly mention that the tool returns a list, but the title and noun-phrase construction make that obvious. The 'Start here' guidance adds practical 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 tool has zero parameters, and the input schema is empty. According to the rubric, a zero-parameter tool gets a baseline of 4 because there are no parameter semantics to clarify. The description does not need to add anything.

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 identifies the tool's purpose: listing events that journeys wait on but which have never arrived. It distinguishes this from sibling tools like list_journeys by focusing specifically on missing events, making it the obvious first step for diagnosing stuck journeys.

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 'Start here' provides explicit usage guidance, indicating this tool is the entry point for investigating blocked journeys. It gives clear context (users stuck forever) but does not explicitly name alternatives or when not to use it, which would merit a 5.

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