Fetch Data from Specific Source

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

Annotations already provide readOnlyHint, idempotentHint, and openWorldHint. The description adds behavioral context: it supports extended data sources and discloses the FRED authentication caveat, which is beyond what annotations provide.

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 well-structured with Args, Returns, a warning note, and examples. Every sentence adds value, and the overall length is appropriate for the tool's complexity.

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?

Without an output schema, the description states '数据源返回的数据' (data returned by the source), which is vague but acceptable for a generic fetch tool. Examples cover major sources, but error handling or pagination is not discussed.

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?

Examples show concrete usage for each source (e.g., source='cnbs' with keyword, source='census' with type and year), adding significant meaning beyond the minimal schema descriptions. Schema coverage is 100% but the description compensates richly.

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 '从特定数据源获取数据' (fetch data from a specific data source) and lists supported sources like cnbs, census, international, department. It distinguishes from siblings (e.g., cnbs_search, ext_fred) by focusing on fetching raw data from a source.

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 explicitly warns about FRED authentication limitations and suggests using ext_fred for HTTP mode. It provides examples for multiple sources, but does not explicitly state when to use this tool versus dedicated ext_ tools for other sources.

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