OpenNews MCP

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It describes the return format ('tree structure with engine types... and their sub-categories'), which is helpful. However, it doesn't mention potential limitations like rate limits, authentication needs, or data freshness. Since annotations are absent, a 4 reflects good but not exhaustive behavioral 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?

The description is well-structured and concise: three sentences that efficiently cover purpose, output format, and usage guidelines. Each sentence adds value without redundancy, and key information is front-loaded. No wasted words.

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?

Given the tool's complexity (simple catalog with 0 parameters), no annotations, and no output schema, the description is mostly complete. It explains the purpose, output structure, and usage context. However, it lacks details on error handling or exact return format specifics, which could be useful for an agent. Still, it's adequate for a low-complexity tool.

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?

The tool has 0 parameters, and schema description coverage is 100% (though schema is empty). The description doesn't need to explain parameters, but it implicitly confirms no inputs are required by not mentioning any. Baseline for 0 parameters is 4, as the description appropriately focuses on output and usage.

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 clearly states the tool's purpose: 'Get all available news source categories and their metadata.' It specifies the verb ('Get'), resource ('news source categories and their metadata'), and distinguishes from siblings by focusing on cataloging sources rather than retrieving or searching news content. The mention of 'tree structure' and engine types provides additional specificity.

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 states when to use this tool: 'Use this first to understand what news sources are available before searching.' This provides clear guidance on its role as a prerequisite for other news-related tools, distinguishing it from siblings like search_news or get_latest_news that retrieve actual news content.

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