hn_top

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds the output format ('markdown list') and the fixed count ('top 5 stories'), which is mildly useful, but it does not disclose any additional behavioral traits such as rate limits, authentication, or network dependencies.

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 concise, using three short clauses to convey when to use, what it returns, and that it takes no parameters. Every sentence earns its place and the key trigger is front-loaded with WHEN TO USE.

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?

For a simple, parameterless, read-only tool with strong annotations, the description fully covers the trigger condition, the output content, and the output format. No additional context is necessary for an agent to select and invoke the tool correctly.

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 tool has zero parameters, so the schema already fully describes the input contract. The description explicitly states 'Takes no parameters,' reinforcing the schema and providing a baseline score of 4 as per rubric guidance.

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 returns the top 5 Hacker News stories as a markdown list, with a specific verb ('Returns') and resource. It also includes a concrete trigger condition ('the user asks what is on Hacker News right now'), which distinguishes it from the sibling tool morning_brief.

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 explicitly provides a WHEN TO USE condition, making the intended usage clear. However, it does not mention when not to use it or mention alternatives such as morning_brief, so it misses the highest bar for usage guidance.

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