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

With no annotations, the description carries the behavioral burden. It discloses the core behavior (counting, and not returning titles) and implies a read-only live operation, but it does not address output format, failure modes, or whether the optional input parameters are ignored.

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 terse, front-loaded sentences with no wasted words. The core operation comes first, and the exclusion is separated for emphasis.

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 has 9 optional parameters and no output schema, yet the description does not specify that no arguments are needed or what exact return shape to expect. The cryptic 'Titles discarded' does not resolve what titles are being referenced, leaving an agent with meaningful uncertainty when invoking the 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?

Schema coverage is 100%, so the baseline is 3. The description adds no parameter-level meaning, and it does not clarify whether any of the 9 optional parameters influence the count. Still, the schema itself provides descriptive explanations for each parameter.

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 states a specific verb ('Count'), a precise resource ('current Hacker News front-page stories'), and an explicit exclusion ('Titles discarded'). This unambiguously tells an agent what the tool does and distinguishes it from generic fetch or validation tools.

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 specialized purpose directly implies when to use this tool: when a count of current HN front-page stories is needed. However, it does not name alternatives, state when not to use it, or acknowledge the many sibling tools with overlapping generic capabilities.

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