The promise is the U.S. Term Limits pledge: as a senator, seek congressional term limits of three House terms and two Senate terms. Adversarial re-verification confirms the FULL rating. Two independent, reachable sources establish the core claims with verbatim quotes: (1) Sheehy's own official Senate legislation page lists the term-limits joint resolution with the exact cited text ("A joint resolution proposing an amendment to the Constitution of the United States relative to limiting the number of terms that a Member of Congress may serve."), and (2) Americans for Term Limits lists "Sen. Sheehy, Tim [R-MT]" verbatim under "19 Senate Sponsor and Cosponsors of S.J.Res. 1." The resolution's substance — exactly two Senate terms and three House terms — is independently confirmed by the congress.gov title and the govinfo bill text, matching the pledge precisely. FULL is correctly calibrated rather than CHAMPIONED: cosponsoring the exact-matching amendment is the affirmative promised act of "seeking" term limits (enacting a constitutional amendment is beyond any single senator), but Sheehy is one of many cosponsors who joined after the original 12 sponsors, with no authorship/leadership evidence, so no upgrade to CHAMPIONED. One defect noted and corrected: the cited Britt-release quote was a reformatted paraphrase, not verbatim; I replaced it with the source's actual verbatim text. The Britt release is only a supplementary source for the 3-House/2-Senate substance (which is independently confirmed) and does not mention Sheehy, so the paraphrase does not undermine the rating. congress.gov/govtrack/legiscan returned HTTP 403 to automated fetch, but the two reachable corroborating sources are sufficient. The outcome does not overstate the evidence.