fetch_news

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

The readOnlyHint annotation already indicates a read-only operation. The description adds the cross-platform vs Arch-only constraint, which is valuable behavioral context beyond annotations. However, it omits details such as return format, pagination, or error behavior. With annotations covering safety, a 3 is appropriate.

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 concise paragraph, front-loaded with '[DISCOVERY]' and a clear summary. Every sentence adds value: tool purpose, action list, and platform constraints. No wasted words or redundancy.

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 moderate complexity (three actions, platform dependencies), the description covers the key behavioral differences and input parameters. No output schema exists, but for a fetch tool this is acceptable. It could briefly mention ordering or error handling for a perfect score, but current level is sufficient.

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?

Input schema coverage is 100%, and the schema already describes each parameter (action enum, limit with default, since_date format). The description reinforces the action meanings and adds cross-platform info, but does not provide new details beyond the schema. Baseline 3 is correct as the schema does the heavy lifting.

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 explicitly states 'Unified news fetching from Arch Linux' and enumerates three actions (latest, critical, since_update), providing a specific verb ('fetch') and resource ('news'). This clearly distinguishes it from all sibling tools, which are focused on other aspects like configuration analysis or package management.

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 gives clear context for when to use each action: 'Works on any system for latest/critical, Arch only for since_update.' This informs the agent about platform dependencies. While it does not explicitly list alternatives, the sibling tools are unrelated to news fetching, so no exclusion is needed.

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