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

Annotations already indicate readOnlyHint=true, and the description adds valuable context: hourly updates, keyless Firebase source, computation basis, and return fields. This goes beyond the annotations without contradicting them.

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 dense but information-dense: two sentences cover output, use cases, and update frequency. It could be slightly better structured with separate lines, but every sentence contributes value.

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?

No output schema exists, so the description lists the return fields (theme_tally, top_stories, etc.), which is helpful. The only parameter is well-documented in the schema. The tool's simplicity and good annotations make this reasonably complete.

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% for the only parameter (days), so the schema fully explains it. The description offers no additional info about the days parameter, including the Gold tier requirement and history behavior, but the schema already covers that, so baseline 3 is appropriate.

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 what the tool does: returns a 0-100 tech-community engagement score with specific fields. It identifies the resource (Hacker News top-30) and output components. However, it does not explicitly differentiate itself from sibling tools, so it falls short of a 5.

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 explicit when-to-use scenarios ('Call when the user asks what the tech community is talking about...') and timing applications (launch post, Show HN). It does not mention when NOT to use it or name alternatives, which prevents a 5.

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