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

With no annotations, the description carries full burden. It explicitly discloses the asynchronous behavior and provides a follow-up action (use get_run). While it lacks details on side effects or permissions, the async disclosure is a significant behavioral trait that goes beyond the schema.

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 tightly written sentences. First sentence states the action and target, second gives the essential async caveat. 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 simple 1-param tool with no output schema, the description explains the async behavior and next steps, but does not explicitly state what the tool returns (e.g., a run ID to pass to get_run). This is a gap given the output schema is absent.

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 coverage is 100% (journeyId is described as 'The journey ID to trigger'), so the baseline is 3. The description does not add extra semantics beyond the schema, but the schema already fully explains the parameter.

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 uses the specific verb 'Execute' and identifies the resource as 'a journey (custom browser test flow)', distinguishing it from siblings like trigger_test. It clearly states the action against the target.

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 gives clear context: the journey runs asynchronously and directs the user to use get_run to check progress. However, it does not explicitly mention alternatives or when not to use this tool, so it falls short of a full 5.

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