ENH: improve 'incompatible tolerance' error message in merge_asof
@leifwalsh can you rebase and use kw args, change to use ``self.tolerance``, no test is necessary here ping # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/17260?src=pr&el=h1) Report
> Merging [#17260](https://codecov.io/gh/pandas-dev/pandas/pull/17260?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/d8129b49b76362ed148938bcb64e095a95aaf19a?src=pr&el=desc) will **decrease** coverage by `0.01%`.
> The diff coverage is `75%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/17260/graphs/tree.svg?height=150&token=eZ4WkYLtcO&width=650&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/17260?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #17260      +/-   ##
==========================================
- Coverage   91.42%   91.41%   -0.02%     
==========================================
  Files         163      163              
  Lines       50068    50068              
==========================================
- Hits        45777    45768       -9     
- Misses       4291     4300       +9
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `89.22% <75%> (ø)` | :arrow_up: |
| #single | `40.35% <0%> (-0.06%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/17260?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/reshape/merge.py](https://codecov.io/gh/pandas-dev/pandas/pull/17260?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvcmVzaGFwZS9tZXJnZS5weQ==) | `94.26% <75%> (ø)` | :arrow_up: |
| [pandas/io/gbq.py](https://codecov.io/gh/pandas-dev/pandas/pull/17260?src=pr&el=tree#diff-cGFuZGFzL2lvL2dicS5weQ==) | `25% <0%> (-58.34%)` | :arrow_down: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/17260?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `97.8% <0%> (-0.1%)` | :arrow_down: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/17260?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/17260?src=pr&el=footer). Last update [d8129b4...a9ac6f9](https://codecov.io/gh/pandas-dev/pandas/pull/17260?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/17260?src=pr&el=h1) Report
> Merging [#17260](https://codecov.io/gh/pandas-dev/pandas/pull/17260?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/d8129b49b76362ed148938bcb64e095a95aaf19a?src=pr&el=desc) will **decrease** coverage by `0.01%`.
> The diff coverage is `75%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/17260/graphs/tree.svg?width=650&height=150&src=pr&token=eZ4WkYLtcO)](https://codecov.io/gh/pandas-dev/pandas/pull/17260?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #17260      +/-   ##
==========================================
- Coverage   91.42%   91.41%   -0.02%     
==========================================
  Files         163      163              
  Lines       50068    50068              
==========================================
- Hits        45777    45768       -9     
- Misses       4291     4300       +9
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `89.22% <75%> (ø)` | :arrow_up: |
| #single | `40.35% <0%> (-0.06%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/17260?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/reshape/merge.py](https://codecov.io/gh/pandas-dev/pandas/pull/17260?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvcmVzaGFwZS9tZXJnZS5weQ==) | `94.26% <75%> (ø)` | :arrow_up: |
| [pandas/io/gbq.py](https://codecov.io/gh/pandas-dev/pandas/pull/17260?src=pr&el=tree#diff-cGFuZGFzL2lvL2dicS5weQ==) | `25% <0%> (-58.34%)` | :arrow_down: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/17260?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `97.8% <0%> (-0.1%)` | :arrow_down: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/17260?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/17260?src=pr&el=footer). Last update [d8129b4...a9ac6f9](https://codecov.io/gh/pandas-dev/pandas/pull/17260?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
