Search the text of downloaded WeChat attachment files for a keyword and return matching content. Performs a read-only scan without altering WeChat files or databases.
在微信已下载的本地文件正文中搜索关键词；只读扫描，不修改微信文件或数据库。
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | ||
| keyword | Yes | ||
| end_time | No | ||
| extensions | No | ||
| scan_limit | No | ||
| start_time | No | ||
| max_chars_per_file | No |
Changes observed during successful MCP inspections.
v4.1.8Input schema / properties / max_chars_per_fileAdded value: +{
+ "exclusiveMinimum": 0,
+ "maximum": 1000000,
+ "type": "integer"
+}v4.1.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false. The description repeats this safety profile with '只读扫描，不修改微信文件或数据库' but adds no behavioral context beyond the annotations, such as scan limits, performance, or return format.
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 a single, front-loaded sentence with no filler. It is efficient, though its extreme brevity contributes to gaps in usage and parameter guidance rather than earning its place fully.
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 7-parameter search tool with no output schema and zero schema description coverage, the description is far too thin. It does not explain how to use filters, time ranges, extension scoping, result limits, or what a search returns, making correct invocation largely guesswork.
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 0% across 7 parameters, and the description explains none of them beyond implying the required keyword. Parameters like limit, scan_limit, extensions, start_time, end_time, and max_chars_per_file are left completely undocumented.
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 clear verb ('搜索关键词') and resource scope ('微信已下载的本地文件正文'), which distinguishes it from message-search and article-search siblings. However, it does not explicitly name or contrast with the closest alternative, extract_wechat_attachment_text, so it falls short of full sibling differentiation.
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 no when-to-use guidance, no prerequisites, and no alternatives. It only describes the operation itself, leaving the agent to infer that this is for searching downloaded WeChat file contents rather than messages or articles.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.