
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
In the Cartesian coordinate system $xOy$, the parametric equation of circle O is 
$$
\begin{cases} 
x=- \frac { \sqrt {2}}{2} + r \cos \theta \\
y=- \frac { \sqrt {2}}{2} + r \sin \theta 
\end{cases}
$$
where $\theta$ is the parameter and $r>0$. With O as the pole, the positive half of the x-axis as the polar axis, and the same unit length, establish a polar coordinate system. The polar equation of line $l$ is $\rho \sin(\theta + \frac {\pi}{4})= \frac { \sqrt {2}}{2}$. Write the polar coordinates of the circle's center and calculate for which value of $r$ does the maximum distance from a point on circle O to line $l$ equal 3.

Present the answer in LaTex format: \boxed{Your answer}
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