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

With no annotations, the description must disclose behavior. It only says 'Titles discarded,' which hints at output filtering but does not explain side effects, rate limits, or how inputs are used. The schema hints that parameters are 'discarded after the shape check,' but the description itself adds almost no behavioral context beyond the purpose.

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 brief—two sentences—and front-loads the core action. It is efficient with no wasted words. However, the brevity leaves critical gaps, which is a trade-off, but for conciseness alone it scores well.

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 nine optional parameters, no required ones, and no output schema. The description fails to explain how to invoke the tool correctly, what input is expected, or what the output format is. It is completely inadequate for an agent to use this tool safely or effectively.

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 each parameter already has a description explaining its role and that it is discarded. The tool description adds nothing beyond that—no additional meaning, syntax, or relationships. The baseline of 3 applies because the schema does the heavy lifting.

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 tool counts current Hacker News front-page stories, a specific verb+resource. However, it does not explain how the nine optional parameters relate to this purpose, and it doesn't distinguish this tool from siblings like web-fetch or fetch-status, which could also interact with URLs. The added phrase 'Titles discarded' is ambiguous—discarded from input or output?

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?

No guidance is provided on when to use this tool versus alternatives. It never mentions alternatives, prerequisites, or typical invocation scenarios. An agent has no basis to choose this tool over similar ones.

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