Diagnose a single Redis key by retrieving its type, TTL, memory usage, and encoding structure.
单键多维诊断工具：聚合获取类型、TTL、内存占用与编码结构。
Args: key: 待诊断的目标键名 connection: 目标连接别名（可选，当前系统仅配置单连接 'default'，缺省直接使用） db: 目标数据库编号（可选，0~15）
| Name | Required | Description | Default |
|---|---|---|---|
| db | No | ||
| key | Yes | ||
| connection | No |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v2.2.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden. 'Diagnostic' implies read-only and it discloses the aggregated facets, but it never explicitly confirms no mutation or state the permission/auth requirements. The connection note (single 'default' connection) is useful context.
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?
One-line purpose up front, then a compact, well-structured arg list. Every line contributes; no padding.
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?
Output schema exists, so return values need no explanation, and parameters are covered. However, with no annotations the description should do more on safety/read-only status and sibling routing; those gaps leave it only minimally complete.
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 0%, so the arg annotations do the work: key is the target, connection is optional with the 'default' fallback explained, and db is given the 0~15 range absent from the schema. This meaningfully compensates for the bare schema.
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?
States a specific verb and resource – single-key diagnosis – and enumerates the aggregated facets (type, TTL, memory, encoding). This clearly separates it from redis_scan_keys (multi-key listing) and redis_execute_command (raw command), though no sibling is named explicitly.
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 no statement of when to use this versus redis_execute_command, which could also return TYPE/TTL/MEMORY/OBJECT ENCODING. '单键多维诊断' implies a diagnostic context, but no alternatives or exclusions are offered.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.