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

Annotations already declare the tool as read-only, idempotent, non-destructive, and open-world. The description adds little beyond the purpose; it does not disclose return format, pagination, or behavior around the count parameter. However, since annotations cover the safety profile, the description is minimally adequate but lacks deeper 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 a single, focused sentence that immediately conveys the tool's function. There is no redundant information or filler. It is highly concise and well-structured.

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?

The tool is relatively simple with two optional parameters and no output schema. The description is adequate but does not explain what a returned 'news item' looks like or how the category filter behaves. Given the lack of output schema, a bit more detail about return values would improve completeness.

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 input schema documents both parameters (count and category) with full descriptions, achieving 100% coverage. The description does not add any additional meaning beyond what the schema provides, which aligns with the baseline score of 3 when schema coverage is high.

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 trending news from X/Twitter.' It uses a specific verb ('Get'), a resource ('X/Twitter'), and a scope ('trending news'). While this distinguishes it from sibling tools like twitter-search or twitter-read, it does not explicitly name alternatives, so it falls short of a perfect 5 score.

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 guidance on when to use this tool versus alternatives such as twitter-search or twitter-read. The description simply states what it does, without providing context on preferred use cases or exclusions. This is a clear gap.

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