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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds the key behavioral fact that it is a relative index, not absolute, which is useful. However, it does not disclose output format or how to interpret rank values.

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 description is concise and front-loaded with the most important caveat (relative vs absolute). Every sentence earns its place, and the bilingual repetition is not redundant—it serves the same message efficiently.

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 tool with no output schema, the description does not explain what the return value looks like (e.g., sorted list, rank score meaning). Also, the anchor is mentioned as 'libraries' but no parameter exists to change it, leaving a potential gap in how an agent would use the tool correctly.

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?

The input schema provides complete descriptions for both parameters (limit and heldOnly) at 100% coverage. The tool description adds nothing beyond what the schema already states, so the baseline of 3 is appropriate.

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 verb+resource: it ranks search-demand, and crucially clarifies it is a relative index anchored to libraries, not an absolute volume. This distinguishes it from sibling search tools like search_data and search_catalog.

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 description gives a clear use case: to compare relative search interest for market/topic research. It also warns against treating it as absolute search volume, implicitly telling the agent when not to use it, though it does not name an explicit alternative tool.

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