Compare Harpd board snapshots (NOT a time series)

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

Annotations already mark this as read-only and open-world, and the description adds substantial behavioral context: only three live period-scoped snapshots exist, no historical time series is available, and rankPoints represent purchased promotional placement rather than quality. This materially prevents misinterpretation of results.

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 well-structured and front-loaded with the core purpose, with clearly labeled warnings for the most important caveats. There is minor redundancy in repeating the 'not a time series' point in both title and description, but the emphasis serves a real safety purpose.

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 read-only tool with no output schema, the description explains what the tool can and cannot return: exposed periods plus an explicit limitation statement. It also clarifies the meaning of rankPoints. It could describe the exact result layout or how productId versus productSlug is resolved, but the essential calling context is covered.

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 explains each parameter. The description reinforces the board comparison context but does not add per-parameter meaning beyond what the schema provides, fitting the baseline for high schema 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 verb 'Compare' plus the direct object 'the three published Harpd Rank board snapshots (overall / monthly / weekly)' specifies exactly what the tool does. The title's '(NOT a time series)' and the discussion of product-level versus board-level comparison distinguish it from ranking/history siblings.

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?

It states when to use the tool (comparing snapshots for one product or side by side at board level) and is emphatic about when not to use it (month-over-month trends, because no multi-month time series exists). It does not name an alternative sibling tool, but the exclusion is unambiguous.

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