[finklen-amazon]

Summary

Changes

cost-explorer had no way to send DimensionKey to GetDimensionValues, so the values of a PRODUCT_ATTRIBUTE key could not be listed. Its description also did not name the ProductAttributes filter leaf.

• cost-explorer takes dimension_key and sends it as DimensionKey (getDimensionValues, dimension=PRODUCT_ATTRIBUTE). If it is omitted or empty, the response lists the keys.
• The description documents:
  • the ProductAttributes leaf and its MatchOptions (EQUALS, ABSENT, CASE_SENSITIVE)
  • that Amazon Bedrock is the only supported service, with keys provider, model, inferenceType, feature
  • that keys and values are case-sensitive, while search_string matches partially and case-insensitively
  • that data starts 2026-09-01: a period that starts earlier fails, even if most of it is later
  • the PRODUCT_ATTRIBUTE dimension-reference entry
• It also documents the results that come back silently, with no error:
  • A wrong key or value returns $0.
  • ABSENT or [""] with a wrong key matches every Bedrock cost.
  • Not and a PRODUCT_ATTRIBUTE group_by cover only Bedrock costs, so their totals do not reach the account total.
  • Group labels have the form key$value.
  • A wrong dimension_key returns only "".
• It documents the SERVICE-scope rule:
  • A SERVICE leaf anywhere must keep the result to Bedrock services.
  • Under And, one such leaf is enough; under Or, every branch needs one; a leaf under Not never counts.
  • getDimensionValues requires such a leaf, paired in an And.
  • Bedrock costs appear under several SERVICE names.
• It documents that the forecasts reject the leaf.

User experience

Before: an agent could not list product attribute values. It had nothing telling it that a ProductAttributes filter exists, and nothing to warn it that a wrong key returns $0, or that Not and ABSENT cover only Bedrock costs.

After: {"operation": "getDimensionValues", "dimension": "PRODUCT_ATTRIBUTE", "dimension_key": "model"} lists the model names, which can then be used in a ProductAttributes filter. The description tells the agent about each of the results above.

Testing

• Unit tests: 4379 passed. New tests cover dimension_key forwarding, and that DimensionKey is omitted when the key is empty, in both the tool and the operation, plus a description contract test for the new text. The existing contract tests now treat PRODUCT_ATTRIBUTE as a key accepted in fewer places.
• Live checks against Cost Explorer: read-only, through the served tool over stdio. Every claim in the new text was checked against the public API reference (GetDimensionValues, Expression, ProductAttributeValues) and with live calls:
  • On this branch: 18/18 claims pass.
  • On main: 13/18. The 5 that fail are the dimension_key claims and the description text. The 13 that pass are regression guards for existing API behavior, such as ProductAttributes filters already passing through the filter argument.

Checklist

• I have reviewed the contributing guidelines
• I have performed a self-review of this change
• Changes have been tested
• Changes are documented

Is this a breaking change? (Y/N) N

RFC issue number:

Checklist:

• Migration process documented
• Implement warnings (if it can live side by side)

Acknowledgment

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of the project license.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.79%. Comparing base (69e2666) to head (1d99fe7).
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4990      +/-   ##
==========================================
- Coverage   93.79%   93.79%   -0.01%     
==========================================
  Files        1080     1080              
  Lines       94712    94714       +2     
  Branches    15442    15443       +1     
==========================================
+ Hits        88833    88834       +1     
  Misses       3505     3505              
- Partials     2374     2375       +1     

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.