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

Annotations already declare readOnly, idempotent, non-destructive and openWorld=false, so the safety profile is covered. The description adds genuinely new behavioral context absent from annotations: results are structured records, pay is expressed in KRW per month unless stated, and null means the advert was silent. Return-data semantics are the right thing to disclose with no output schema.

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?

One dense sentence front-loads the board and scope before the facet list, then a second sentence covers return semantics. No filler, though the facet enumeration is somewhat list-like rather than prioritized.

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 15-parameter, no-output-schema filter tool the description covers return format, currency, and null meaning, which is the most valuable missing piece. It still omits pagination behaviour (page/limit), default ordering, and what happens when no filters are supplied, leaving real gaps.

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 only 47% across 15 parameters, so the description must compensate. It names the filterable facets (region, student age, housing, visa, schedule, contract, setting, direct hire, minimum salary, free text), which helps map intent to parameters, but it adds no syntax, default, or combination guidance beyond the enumerations already in 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?

"Filter the live LucyESL board of English-teaching jobs in South Korea" gives a specific verb (Filter), resource (job board), and domain scope, and then enumerates the filterable facets. It is clear enough to call, but it does not distinguish itself from the sibling named 'search', so an agent cannot tell the two apart from this text alone.

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 facet list implies the tool is for browsing/filtering, but there is no explicit when-to-use, when-not-to-use, or pointer to siblings such as get_job for a single posting or salary_stats for aggregates. The agent is left to infer routing.

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