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

With no annotations, the description carries the full burden of behavioral disclosure. It only notes 'Titles discarded,' which hints at some input ignoring but does not explain that all parameters appear to be discarded or irrelevant. There is no mention of side effects, prerequisites, or what the returned count represents.

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 extremely short (two sentences), which is concise, but it is under-specified rather than efficiently structured. It does not provide the necessary context to understand the tool's behavior or parameter relevance, so the brevity works against it.

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 parameters, no output schema, and no annotations, yet the description provides almost no operational detail. It does not explain what the tool returns, how the parameters are used, or why they exist. An agent cannot correctly invoke this tool with confidence, making the description inadequate for the complexity.

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 does not add any meaning beyond the schema; it only mentions 'Titles discarded' which applies to the feed parameter but not the others. It fails to clarify how the parameters relate to the tool's purpose, but the schema itself already documents 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 and resource ('Count current Hacker News front-page stories'), which is clear on the surface. However, it is misleading because the input schema contains nine unrelated parameters (URL, city, file path, timezone, etc.) that have no obvious connection to counting HN stories. The description does not reconcile this mismatch, so an agent would be confused about what the tool actually does.

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 the many sibling tools (e.g., domain-shape, search-query-len, weather-hint). The description does not mention any conditions, alternatives, or exclusions, leaving the agent without any decision framework.

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