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

With no annotations, the description carries the full burden. It says 'Titles discarded' and 'Count current' but doesn't disclose what the return value looks like, whether it makes a network request, or any side effects. The phrase 'Titles discarded' hints at a behavioral trait, but it's minimal and doesn't explain the output format or 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?

The description is very short and front-loaded with the core purpose. 'Titles discarded' is a useful clarification. It's efficient, though it could arguably include a bit more context without becoming verbose.

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?

Given the tool has 9 parameters, no output schema, and no annotations, the description is too sparse. It doesn't explain what the tool returns, how the parameters relate to the counting, or why so many parameters exist. An agent would struggle to know what to pass and what to expect back.

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 the schema already documents all 9 parameters. The description adds no parameter-specific meaning beyond the schema. Baseline 3 is appropriate since the schema does the heavy lifting, and the description doesn't need to compensate.

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.' This clearly identifies the tool's purpose. However, it doesn't explicitly distinguish it from siblings like fetch-status or web-fetch, though the HN-specific scope is fairly unique.

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 given on when to use this tool versus alternatives. The description doesn't mention any context, prerequisites, or exclusions. An agent would have to infer that this is for HN front-page counting, but there's no explicit routing or comparison to sibling tools.

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