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

With no annotations, the description carries the transparency burden. It discloses that titles are discarded and implies a read-only fetch of current data, but it does not explain the return format, whether optional parameters like 'feed' change the source, network dependence, or failure behavior.

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 two short sentences with the primary action front-loaded and a key limitation stated immediately after. There is no redundant or filler content; every word contributes to understanding the tool's scope.

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 core action is simple and clearly stated, but with no output schema and no annotations, the description should clarify what the return value looks like and how the nine optional parameters relate to the count. The schema descriptions help, but the tool-level guidance leaves those gaps.

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 the schema already documents every parameter, making 3 the baseline. The description adds little parameter-level guidance, though 'Titles discarded' echoes the 'feed' parameter's description and hints at its relevance.

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 uses a specific verb ('Count') and a specific resource ('current Hacker News front-page stories'), so an agent immediately understands the tool's core function. The added clause 'Titles discarded' further narrows the scope and distinguishes it from tools that would return story details.

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 provides clear context for when to use the tool: when a current count of HN front-page stories is needed. It also implies an exclusion because titles are discarded, but it does not name alternative tools or state explicit when-not conditions.

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