top_cost_drivers

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

No annotations are provided, so the description must carry the burden, and it does: it declares read-only behavior, states the exact result shape (rows, usd_complete, unpriced_skus), and flags the list-price-vs-applied-discount caveat. The unpriced_skus/usd_complete flags are valuable partial-data disclosure; only auth/permission requirements are unaddressed.

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?

Three short sentences, front-loaded with the resource and window, then safety/return contract, then the routing hint. No filler and each sentence carries distinct 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 one-parameter, no-output-schema analytics tool, everything an agent needs to call it correctly is present: scope, time window, read-only status, price basis, and the shape of the returned object including partial-pricing flags.

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 0%, so the description must compensate, and it adds the key constraint the schema lacks: the valid range 1..365 for `days`. It omits how out-of-range values behave, but the default (30) is already in the schema, so the critical semantics are covered.

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 concrete resource (top 20 jobs, warehouses and clusters ranked by list-price cost) plus the time window, which is a specific ranking query rather than a generic summary. It distinguishes itself from find_waste but does not clarify how it differs from cost_summary or cost_review_report, which appear to cover adjacent ground.

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?

Gives an explicit use case ("answer 'what spent the most?'") and sequences it before find_waste ("before drilling into waste"). It provides clear context but no exclusion of when cost_summary or cost_review_report would be the better pick.

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