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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false, closed world), so the bar is lower. The description adds a genuinely non-obvious semantic caveat: the value is a relative index anchored to libraries, not an absolute search volume. That is the single most likely misinterpretation of the output and the description preempts it.

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 English text is front-loaded and every sentence earns its place, with the critical caveat ('NOT an absolute search volume') placed before the use-case guidance. The full Korean mirror of the same text roughly doubles the length without adding information, which keeps it from a 5.

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, the description carries some burden for explaining what comes back, and it only says the output is an index relative to an anchor without describing the record shape, ranking direction, or scale. For a simple 2-parameter, no-required-parameter read tool this is adequate but not complete.

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% and both parameters (limit, heldOnly) are documented in the schema, so the baseline is 3. The description adds no parameter-level detail beyond what the schema already states, though the mention of the 'libraries' anchor loosely frames what heldOnly/topic results mean.

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 resource and metric ('Search-demand ranking') and immediately clarifies what the metric actually means ('an index relative to an anchor (libraries), NOT an absolute search volume'). That is more precise than the bare tool name. It does not explicitly differentiate from siblings, but none of the listed siblings (search_catalog, list_regions, benefits_*) overlap with a demand-index metric, so differentiation is not really needed.

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 one affirmative use case ('compare what people look for more, for market or topic research'), which tells the agent the intended context. However, it names no alternatives and states no conditions under which this tool should NOT be used (e.g., vs. search_catalog for retrieving actual records). Usage is implied rather than bounded.

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