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

With no annotations provided, the description carries the full burden of disclosing behavioral traits. It does not mention side effects, permissions, rate limits, or any other operational details, leaving the agent without critical information about the tool's runtime 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 concise, consisting of two short sentences. It avoids unnecessary verbosity, though the second sentence ('Titles discarded.') is somewhat cryptic and could be integrated more clearly into the main statement.

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 fails to explain what these parameters do or what the expected output/results look like. This leaves the agent without essential context to call the tool effectively or interpret its outcomes.

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?

The schema lists 9 parameters, each with a description, but these descriptions are entirely mismatched with the tool's purpose (e.g., 'Git ref name', 'City name for a public weather hint'). They appear to be placeholders from a template and provide no meaningful semantic explanation of how the parameters relate to counting Hacker News stories, effectively misleading the agent.

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 clearly states the action ('Count') and the target ('Hacker News front-page stories'), making the tool's purpose immediately understandable. The phrase 'Titles discarded' adds a minor ambiguity, but the core intent is unmistakable.

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 no guidance on when to use this tool versus any alternative. It lacks any mention of conditions, prerequisites, or scenarios where this tool is preferred or required.

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