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

With no annotations, the description must carry the behavioral burden. It discloses a key behavioral trait ('Titles discarded') and implies live/current data, but it does not state that the 9 optional parameters are effectively ignored or describe the return format or possible failure modes.

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?

Two short sentences with the core action first and the limitation second. There is no filler, and every word contributes to the tool's meaning.

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 description is adequate for a trivial read-only count operation, and no output schema exists, so the return value is only implied by 'Count'. Missing context includes whether all parameters are ignored and whether the count is live or cached.

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 coverage is 100%, so the baseline is 3. The description adds little beyond the schema; 'Titles discarded' echoes the feed parameter's note but does not clarify how the count relates to the many unrelated optional parameters.

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 opens with a specific verb and resource: 'Count current Hacker News front-page stories.' This identifies exactly what the tool does and is distinct from sibling tools, none of which target HN front-page counting. 'Titles discarded' further clarifies the scope of the result.

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?

It clearly indicates use for obtaining the current count of HN front-page stories. 'Titles discarded' implies it should not be used when story titles are needed, but it does not name alternative tools or give explicit exclusion conditions.

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