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

Beyond readOnlyHint/openWorldHint, the description discloses pricing (70 points per call) and a non-obvious failure mode: if the scan cannot cover all ranges needed to determine rank, the call fails with no result and no charge. It stops short of describing the return payload for a tool 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?

The core purpose is front-loaded in the first sentence, followed by operational constraints. The English/Korean duplication is expected for a bilingual catalog but does add length without adding information.

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 two-parameter read-only lookup with full schema coverage, the definition covers purpose, cost, and failure semantics. The main remaining gap is that, with no output schema, it does not say what a successful result contains beyond an implied rank position.

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 coverage is 100% and both parameters are documented with an example and a length bound, so the schema carries the semantics. The description adds no parameter-level detail beyond what the schema already states, making the baseline 3 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 precise verb and resource — find where a domain ranks (1-100) in Google results for a keyword — with explicit scope (top 100) and inputs (keyword, domain). This is clearly distinct from siblings like google_search or google_image_search, which return results rather than a rank position.

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 establishes clear operating context: a per-call cost of 70 points and the condition under which the call fails without being charged. It does not explicitly name alternatives (e.g. google_search for raw SERP data) or state when not to use it, so it falls short of a full when/when-not treatment.

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