按关键字搜索表和列

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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint). The description adds useful behavioral context beyond those: matching spans three attributes, results include owner table/type/comment, and Chinese comments are searchable. No contradiction with annotations.

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?

Two compact sentences in Chinese, front-loaded with the search scope and immediately followed by practical examples. Zero fluff; every word contributes to understanding the tool's purpose and usage.

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 read-only search tool with full schema coverage and safety annotations, the description adequately covers behavior, return fields, and usage scenarios. Pagination and offset/limit are documented in parameters, and since there is no output schema, the returned fields are stated. Nothing essential is missing for correct invocation.

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 100%, so parameters are fully documented in the schema. The description's mention of keyword matching across three attributes duplicates the schema's keyword parameter description, adding minimal new semantic value beyond what the schema already provides.

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 (跨表搜索) and resource (tables and columns), and specifies the matching criteria (表名、列名、列注释) and return contents (所属表、列类型、注释). This fully distinguishes it from siblings like dm_list_tables (table listing) and dm_describe_table (single-table detail) without ambiguity.

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?

Concrete example queries ('哪个表里有手机号字段', '跟退款相关的列在哪') clearly signal the exploration/discovery use case, and the '跨表搜索' phrase implies cross-schema scoping. However, it does not explicitly name alternatives or exclusion criteria, so it lacks the top-tier explicit routing.

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