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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, open-world), so the bar is lower. The description adds the useful 'real-time' freshness signal but says nothing about refresh cadence, data source, coverage gaps, or rate limits.

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?

Front-loaded with the core resource and a compact enumeration of returned metrics plus example phrasings. The bilingual glosses (자치구, 좋음/나쁨) add value, though the list is slightly dense.

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 zero-param, no-output-schema lookup, the description covers the resource, the metrics returned, and the query shapes. Missing only freshness/cadence details that an agent might want before relying on it.

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?

Zero parameters, so the baseline is 4. Nothing to document, and the description correctly implies the tool takes no inputs by presenting it as a direct lookup.

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 resource (real-time air quality in Seoul districts), enumerates the exact pollutants and index returned, and gives the local-language district term. It is clearly distinguishable from the other seoul_* siblings (dataset, events, real estate).

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?

Provides example query phrasings ('air quality in Seoul / <district>', 'Seoul PM2.5 right now') that signal the triggering context. It doesn't explicitly state when-not-to-use or name an alternative sibling, so it stops short of a 5.

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