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

Annotations only declare readOnlyHint=true, so the description must carry the rest, and it does disclose the return shape (total found plus a list) and the identity fields needed for follow-up calls. It does not discuss result ordering, relevance behavior, or whether an empty total means no matches versus a failed query, but for a read-only search that is a modest gap rather than a serious one.

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: the first states the search scope, the second states the return payload and the follow-up keys. Nothing is redundant and the scoping information is front-loaded.

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 no output schema, return-value explanation falls to the description, and it covers total count, list contents, and the key/employer slug/URL per item. For a five-parameter, all-optional read-only search this is close to complete; ordering and pagination semantics beyond limit are the only noticeable omissions.

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%, so all five parameters (what, where, limit, employment_type, posted_within_days) are already documented with examples and ranges in the schema. The description adds only the high-level framing that filtering is by job and place, so the baseline of 3 applies.

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 ("Search current vacancies") plus a geographic scope ("in the Netherlands") and the filter axes (job, place). The closing clause links results to the get-vacancy and get-employer siblings, which implicitly separates this lookup/listing tool from the detail-fetch tools without naming a competing search alternative.

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?

Usage is only implied by the phrase "Search current vacancies ... by job and place"; there is no explicit when-to-use, when-not-to-use, or statement of prerequisites such as authentication or regional availability. The one genuinely useful routing hint is that each result's key and employer slug feed get-vacancy and get-employer, which establishes the search-then-fetch workflow.

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