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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds useful content-level context ('sanitized description', 'structured facets'), but says nothing about behavior on unresolvable or non-allowlisted ids.

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 sentences, front-loaded with the verb and return content, then the identifier forms. No redundant or filler wording.

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?

With an output schema present, return values need no explanation, and the single parameter is fully documented in both schema and description. The only omission is failure behavior for invalid or non-allowlisted identifiers, which is minor for a read-only fetch.

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%, so the accepted id forms are already documented. The description goes slightly beyond by explaining that click_url is the link to the vacancy on LexGO and that ids typically originate from search_jobs, which clarifies provenance rather than repeating the schema.

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 a specific verb and resource ('Returns one vacancy') plus what it returns ('full sanitized description and structured facets'), and names the accepted identifier forms. It is clearly distinguishable from the sibling search_jobs, which returns multiple results.

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 'click_url from search_jobs' implicitly routes the agent: get ids from search_jobs first, then fetch detail here. There is no explicit when-not-to-use or statement about what happens with an invalid id, so it stops short of full guidance.

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