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

Annotations already declare readOnlyHint=true, so the read-only nature is covered. The description adds no additional behavioral context, such as authentication requirements, rate limits, or what the profile contains. It contributes no value beyond what the annotations and the verb 'Get' already convey.

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 a single, clear sentence that is perfectly concise and front-loaded. Every word earns its place, with no fluff or redundancy.

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 get operation with one parameter and no output schema, the description is minimally adequate. It names the resource but does not hint at what fields the profile contains or any edge-case behavior. It's sufficient for an agent to know it fetches a user profile, but it lacks depth that more complex tools would require.

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%, with the username parameter already described as 'Hacker News username (case-sensitive)'. The tool description adds no further detail about the parameter, so it doesn't enhance schema semantics beyond the baseline for high coverage.

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 ('Get') and the resource ('Hacker News user profile'), with the parameter 'username' implied. It is unambiguous and distinguishes from sibling tools that fetch comments or submissions, though it doesn't explicitly name alternatives.

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 related Hacker News tools like hackernews_user_comments_list or hackernews_user_favorites_list. The description simply states what it does, leaving the agent to infer usage context without explicit exclusions or alternatives.

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