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

Beyond the annotations, the description discloses that results are always partial (Google returns only top rows), that every response carries a data_availability value with five defined states, that no_rows and access_error do not mean zero, that the date range is inclusive in US Pacific time, that each call consumes a token, and that the call creates an XBOSS task and stores results. The early claim '읽기만 합니다' (only reads) is then corrected by the later statement that the call is not purely read-only, which does align with readOnlyHint=false, but the internal tension briefly muddies the safety story.

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 purpose and the data_availability semantics are front-loaded, which is good. The description is still heavy: a long English idempotency-key block interrupts an otherwise Korean description, and the token-cost plus XBOSS-task sentences overlap in what they convey. Some pruning would improve scanability.

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 and nine parameters, the description does the needed work on return semantics: partial results, the five data_availability values, and the time-zone basis. The remaining gap is paging, since start_row exists for iterating but the description never explains how to walk past the top rows Google returns.

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%, so the baseline is 3. The description earns above baseline by adding the Pacific-time basis for start_date/end_date and by fully explaining request_idempotency_key, whose schema entry merely points back to the description. It adds nothing for dimensions, row_limit, or start_row, which remain schema-only.

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 opening sentence names a specific verb and resource: retrieve search performance (impressions, clicks, queries) for a single Search Console site. An agent can tell it apart from the sibling index_status tool. It stops short of naming any alternative explicitly, so it lands at clear-but-undifferentiated rather than a 5.

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?

There is one concrete conditional instruction: if the result is no_rows, widen the date range and call again. The idempotency-key paragraph also tells the agent when to reuse versus regenerate a key. However, nothing routes the agent between this tool and the other performance/report siblings, so the when-to-use guidance is implied rather than explicit.

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