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

Annotations already declare readOnlyHint=true, so the safe-read nature is covered. The description adds useful behavioral context by naming the return fields (journey, status, timestamps), but it does not disclose error/not-found behavior or output format. Since annotations cover the safety profile, this is adequate but not exceptional.

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?

A single 11-word sentence that front-loads the verb and resource, states the identifier method, and lists the key return fields. No filler or repetition of schema details.

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 single-parameter get tool with readOnly annotation and no output schema, the description is largely complete: it states what the tool does and what fields the result contains. It could optionally mention not-found behavior or explicitly route to list_journey_runs for enumeration, but nothing essential 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% and run_id is already well described as 'The journey run id'. The description only reinforces 'by id' without adding format, examples, or lookup semantics. Baseline 3 is appropriate given the schema carries the semantic weight.

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 explicitly that it retrieves a single journey run by id and enumerates the returned aspects (journey, status, timestamps). This clearly distinguishes it from siblings like get_journey, list_journey_runs, and list_journey_run_steps without requiring schema inspection.

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 implies the usage: when you have a run_id and need a single run's details. However, it does not explicitly mention alternatives or when-not-to-use, such as 'for listing runs use list_journey_runs'. The sibling names provide context, but the description itself leaves exclusions to inference.

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