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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is clear. The description adds the qualifier 'published' (only published resources), which is useful, but it does not disclose other behaviors such as error handling or whether currency affects output. With rich annotations, the description contributes modestly.

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 two sentences long, front-loaded with the primary action, and contains no filler. Every word contributes to understanding the tool's scope and usage.

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?

This is a simple get-by-slug tool with strong annotations and no output schema. The description covers the core purpose and the main alternative. It falls short only in not explaining the currency parameter or potential edge cases, but for its simplicity, it is largely complete.

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 0%, so the description must compensate. It explains 'by slug' for the slug parameter, which is helpful for the required field, but the optional currency parameter is not mentioned at all. The enum in the schema provides some self-explanation, but the description adds limited parameter-level context.

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 states the tool retrieves a single published journey, residence, group programme, or package by slug. It uses a specific verb ('Get') and resource list, and distinguishes itself from sibling list_journeys by specifying 'one'.

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 explicitly directs users to list_journeys when the slug is unknown, providing a clear when-to-use alternative. This is strong guidance for tool selection.

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