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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds useful behavioral context by listing the returned fields, including a vacancy_url, and by clarifying that company contact details are not returned — a meaningful boundary for the agent. It does not mention auth or rate limits, but those are not essential here.

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 tightly written sentences. It front-loads the purpose and return fields, then immediately follows with usage and exclusions — no wasted text.

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 read tool with no output schema, the description is complete: it names the input source, lists the key returned fields, and rules out the two most likely wrong uses. An agent has everything needed to call it correctly.

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% and the single vac_id parameter already has a description pointing to search_maritime_jobs or matched_vacancies. The description repeats that same sourcing information, adding little beyond the schema; baseline 3 is appropriate when the schema does the heavy lifting.

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 states a specific verb and resource ('Get the details of one Krew Guru vacancy by its vac_id') and enumerates exactly which fields are returned. It also explicitly distinguishes this from the sibling search_maritime_jobs, so an agent can select it without opening any schema.

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?

It gives explicit when-to-use context: after search_maritime_jobs or when a vacancy comes from create_seafarer_profile_draft (matched_vacancies). It also states clear exclusions — not for searching (use search_maritime_jobs) and not for company contact details, which are not returned.

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