search「Zippa（ジッパ）」のページから、言葉に当てはまる箇所を抜粋つきで探します。Zippa は、計測タグを 1 本貼るだけでサイトの表示速度を改善する無料のサービスです。高速化の機能、無料スピード計測、管理画面の使い方と数字の読み方（操作マニュアル）、お知らせ、利用規約、プライバシーポリシー、運営会社を探せます。Zippa やサイトの表示速度の改善について質問されたら、まずこれを使ってください。言い換え（値段→価格・料金など）にも対応します。
| Name | Required | Description | Default |
|---|---|---|---|
| query | Yes | 探したい言葉（例: 料金 支払い方法） |
| Name | Required | Description | Default |
|---|---|---|---|
| results | Yes | ||
| candidates | No |
Changes observed during successful MCP inspections.
Output schema / properties / candidatesAdded value: +{
+ "items": {
+ "properties": {
+ "id": {
+ "type": "string"
+ },
+ "title": {
+ "type": "string"
+ },
+ "url": {
+ "type": "string"
+ }
+ },
+ "required": [
+ "id",
+ "title",
+ "url"
+ ],
+ "type": "object"
+ },
+ "type": "array"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the bar is lower. The description adds genuinely useful behavior beyond that: excerpts are returned, the tool handles synonyms/paraphrases (値段→価格・料金), and it enumerates the content corpus it searches over.
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?
Purpose is front-loaded in the first sentence, followed by corpus scope, usage guidance, and query behavior. It is efficient overall, though the marketing-flavored middle sentence describing Zippa as a free service is somewhat tangential to invocation.
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?
An output schema exists, so return values need not be explained, and annotations carry the safety profile. Combined with the corpus scope and usage trigger, the definition is nearly complete; the only meaningful gap is that it never distinguishes itself from the search_pages sibling.
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 there is a single required parameter, so the schema already documents 'query' fully. The description adds only the paraphrase-handling note beyond the schema's own example, so the baseline 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 (探す/検索) and resource (Zippa サイト内), and specifies that results come with excerpts (抜粋つき) and support paraphrase queries. It clearly conveys what the tool does, but does not differentiate itself from the similarly-named sibling search_pages, which an agent could easily confuse it with.
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 explicit routing guidance: 'Zippa やサイトの表示速度の改善について質問されたら、まずこれを使ってください' (use this first for Zippa/speed questions). However it names no alternative and offers no when-not conditions, leaving the search vs search_pages and search vs fetch distinction unresolved.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.