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

readOnlyHint=true already tells the agent this is a safe read, so the description only adds that it maps to a dimensions-less query endpoint—useful but thin. It says nothing about response shape, pagination, or result limits, which the annotations do not cover.

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 tight sentences with the core purpose front-loaded and the API mapping trailing as supporting detail; no filler. Slightly more value could have gone into routing guidance instead of the endpoint path.

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?

A simple read-only tool with 4 fully documented parameters and annotation-covered safety; the agent has enough to call it correctly. The one gap is explicit routing to the dimensioned sibling tool, which would make the toolset selection unambiguous.

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%, and the description adds no parameter detail beyond restating that metrics and a date range are involved. Per the rubric, a 3 is the baseline when the schema already documents every parameter.

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 and resource ('aggregate totals for the given metrics over a date range') and pins the underlying endpoint (POST /api/v2/query with no dimensions). The '(no group-by)' qualifier implicitly distinguishes it from an ungrouped-vs-grouped pair, but it never names the sibling that does group-by, so the differentiation is left to inference.

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 '(no group-by)' parenthetical and the 'Convenience' framing imply this is the tool to reach for when you only want grand totals, but no alternative tool is named and no when-not-to-use condition is stated. Usage is implied rather than directed.

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