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

Annotations already declare readOnlyHint and openWorldHint, and an output schema covers the return shape. The description still adds the meaningful behavioral note that facets honor "the same filters as the search tool," which explains aggregation scope. It does not add auth or rate-limit context, keeping it short of a 5.

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?

Two sentences, zero waste, with the aggregation semantics front-loaded and the alternative tool named in the second sentence. Every clause carries information.

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 faceted aggregation tool with full schema coverage, an output schema, and read-only annotations, the description covers purpose, usage, and the sibling relationship. Only a note on how the returned counts are ordered/sized would make it fully 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%, so the schema already documents all 12 parameters including allowed facet values, date formats, and the page*page_size limit. The description only names the three facet values, adding nothing beyond the structured fields; 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?

States a specific verb ("Aggregate"), a specific resource (BBB Scam Tracker reports), and the exact output shape (counts by scam_type, state or country). It also names the sibling search tool it complements, so an agent can tell it apart without opening either schema.

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?

Explicitly gives two use cases (list the scam types present, size a date range) and routes the agent to datasets_bbb_scamtracker_reports_search for paging. The when-to-use and the alternative are stated outright.

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